It would have been easier if Electrum can get its own coinjoin which would have made this easier. But you can still make use of a mixer to mix the coin. Send some of the coins to a mixer and let the mixer send you mixed coin which you can use to spend in the restaurant.

Or make use of exchange like https://exch.cx/ to convert the bitcoin (that you want to use in the restaurant) to monero and back to bitcoin and use it for the spending.

You can also convert to monero and back to bitcoin on https://bisq.network/

If the restaurant is using Binance which I believe most of them might use. Then you have to send the potion or the unit of Bitcoin you want to spend at the restaurant to your Binance and when you reach the place and after eating then you ask the restaurant attendant to give you their Binance Wallet ID and not the Bitcoin address but the Binance Pay ID then you send the coins to the ID and that is all. And nobody can trace and know how much coins is in your country. And if that method can't work then I don't think there is any other way again because if you mix your coins to another wallet it will delay you. Because some mixers took the whole day to mixed, just like one I used the last time. And if you use mixer, you must have two Wallets, one for spending and one doe receiving and hodling. And the spending wallet, you won't keep much coins there since you don't want the restaurant attendants to know the total amount of Bitcoin in your wallet.

There is no other way but to send that first to another wallet, that's how you're going to hide your address. So, before going to a restaurant, transfer it to a wallet where you'll use it for payments and leave the rest there. Only send the amount that you may want to spend for your ease. That's why if you're going to do this, you should have planned it before going out so that you're going to check the fees.

It's not ideal to do it at most times that you'll transfer here and there because the fees are not that worth it. But if they only cost some centavos, it's easier to do that and the fees won't matter at all.

This is also a good suggestion, Binance Pay. An off chain transaction but of course, you'll have to deal with KYC and verifications.

Binance wallet ID, Binance Pay ID don't protect your privacy. This feature is for internal transfer and only can help you to save withdrawal fee from Binance.

It has nothing in protection on your privacy and you can not expect to gain privacy protection when you are using a centralized exchange and even KYCed there with your account. Both accounts of you and the restaurant are KYCed by Binance and the third company used by Binance for KYC processing. If government wants, they can ask your identity from Binance.

And there will be data breaches from Binance or the third party company, so your privacy is not protected.

Do you only want to spend from your electrum down to the service provider wallet ? If yes then you need to do all the privacy stuff before you get to the place you want to buy your goods or you want to exchange your bitcoin for any service.

Just as few others have suggested I will add to it by saying you will need to move some of those your bitcoin with extra fee to a non KYC exchange address where you can withdraw from this exchange to a different address were you can use later at any place were you will send directly to the place wallet.

Or better still just use a mixing service and get the coin detach from your original wallet where only you and the mixer will know the new wallet and were the holdings are originally from.

Electrum wallet was not designed to enhance privacy, so if you want to enhance it, you must connect via Tor only or use Electrum-Server^[1]  to ensure that no third party collects information about your addresses.
After that, use the coinControl feature to ensure that sending is from specific addresses and mix your currencies either in centralized ways, such as transferring them to Monero, using a mixer, coinJoin, or using a P2P crypto DEX like BISQ.

[1] https://electrumx.readthedocs.io/

Use Electrum wallet with Tor to enhance Privacy.

Using Electrum through Tor
Tutorial: How to use Electrum wallet (for advanced users)

HD wallet is not enough to secure your privacy. You need more than a wallet to secure your privacy.

Coin Join, Tor connection and good practice with your inputs, outputs and don't reuse your address.
Some advice for privacy from Blockchair.com

Privacy

First of all, you should always use a new address for EVERY transaction you receive.

So, if that 0.1 BTC was received as 5 separate payments of:

• 0.0301 BTC
• 0.0039 BTC
• 0.0408 BTC
• 0.0019 BTC
• 0.0233 BTC

Then you can just use the two smallest outputs (0.0301 BTC + 0.0019 BTC = 0.0058 BTC) to fund your transaction. In this way, the entity will see no link at all to the three larger outputs under your control.

Or, if you prefer, you could use just the 0.0233 BTC output to fund the transaction, significantly reducing the visibility from the full 0.1 BTC to just 23% of your balance.

Now, if you have only ever received a single transaction, and the amount of that single transaction was 0.1 BTC, then maintaining privacy of that balance will be more difficult.

If you're willing to pay repeated transaction fees over many days/weeks/months/years to gain some privacy, one thing you could do to increase your privacy a bit would be to generate a random time and then after waiting that amount of time from receiving your initial transaction create a new transaction to split your balance by a random percentage and send each portion to a new addresses in your wallet. Then after another random time, chose one of the two outputs randomly, and split that to 2 new addresses. Then after another random amount of time, chose one of the three outputs in your wallet and split that to 2 new addresses, and so on until you have several random sized outputs all created at random different times from random earlier outputs.  This will make it much more difficult for the entity to distinguish between outputs that you still control.

If you're only trying to maintain privacy from one particular entity, and you don't mind another entity knowing about your larger single UTXO, you could briefly send your 0.1 BTC to a popular entity that pools the bitcoins they receive (such as an exchange or a gambling website). As an example, let's assume you use Coinbase. Then you could withdraw random percentages of the 0.1 BTC, each to a separate address in your wallet. It would become extremely difficult for the entity you are trying to maintain privacy from to determine which of the many, many outputs Coinbase sent were sent to addresses of yours vs. addresses of other people.

Another option might be to use an intermediary (friend?, family?, etc) that you aren't concerned about knowing how much BTC you have in the transaction you received.  You could make an arrangement for the intermediary to make the payment on your behalf, and then later you could send a payment amount to the intermediary at a new address compensating them for helping you.

There are probably more options, but those are the few that come immediately to mind.

Note: if the entity you are trying to maintain privacy from is a government entity, it's possible that some of these processes to hide the source of funds might be considered "money laundering" by some governments. This may be illegal in somme jurisdictions, and you may need to talk to a lawyer to make sure that you're not doing anything that could be charged as a crime.

Why should you pay him in bitcoin when you can pay him with other alternative altcoins? After all, you don't want other people to know your total bitcoin balance in the wallet address to be used, which can be seen in the blockchain explorer.

It's impossible that you don't know that bitcoin is not the only cryptocurrency that can be paid to other people. I can understand you if Bitcoin is the only crypto in this industry. That's why there are many options like Ethereum, BnB, Matic, USDT, and others that can be paid online.