Are cards ok to do restaurant because once I pull of a deck of cards the spectator says "O I know a card a trick, let me try"

I think you just answered your question...
-Tyler

Of course cards are suitable for restaurants. Your restaurant routines should contain different props. Performing only with cards or only with coins is not your best bet for a restaurant magician; there should be a mixture. You can add some card magic, coin magic, and sponge ball magic in your routines for example.

As far as the type of spectator that will go, 'Hey, I know a card trick!' I pretty much doubt that will happen in a restaurant, especially if you give the customers the impression that you are a professional magician. But first buy a source that will give you information about restaurant welkaround magic, and also go see a restaurant magician in action. You will learn a lot. Then you can think of being a restaurant magician yourself.

you are paid to entertain.

If they want to show you a trick....enjoy yourself by getting paid and they are doing the work.

Plus what sort of entertaiment is it if you dont let them do anything they want.

Don't start with a card trick. Prove yourself to be a professional first. Then pull out the cards. They won't consider their cheesy card trick to be any comparison to your magic, and therefore will not want to do it.

I like this approach. I would start with something flashy to get their attention but sometimes going with cards first works too. You just need to do an effect first and then if they still want to try let them do it.

It's really just about being able to control your audience. I agree that you can prove yourself with a card trick. In the past I've entertained myself by allowing a cocky spectator show me a trick. It's really quite funny. After they show me a trick. They immediately want and try to tell me how they did it. I don't let them. I assure them that I already know how it's done (even if I don't). In most cases, I do know how it's done. But occassionally I don't know exactly. The truth is, I don't really care how it's done. I don't want to know the secret just to know the secret. What's the point of them telling me and everyone at the table how they did a trick. Anyway, back to the topic. Doing a card trick, first, can work with the right amount of audience control. And if they do happen to get your cards to show you a trick, I just tell them that it's pretty good...and then follow it up with a "Nockem Dead" card trick. I think it is important for there to be a fine line between spectators and magicians. And we know that a magician would never say to another magician, "Hey, let me show you a card trick" in front a bunch of other people.
Another possibility would be to do a trick that doesn't use a full deck. Have the cards separated ahead of time....like maybe the four aces. Though I prefer to pull the cards from the deck, this approach could still work. No one is going to say, "Hey, let me show you a trick with those few cards you have there."

Please don't take this advice straight from me because i'm a new person to magic, but if someone more knowledgeable backs this up then yeah. But personally i'd just start out by doing a very short routine involving XCM, because nothing is more "flashy" with cards than XCM. Then i'd do the trick.

Not everyone is in to XCM. However, that would probably work just as well. Be careful though. You don't want to come off as being too cocky. Many people will view that as just showing off...and in a sense...it is. But not everyone will like that.

I still prefer to start off with something non-card related. Then when I'm ready, I'll introduce the cards by saying something like, "Could you imagine a magician without a deck of cards? Well me neither." Then I'd pull them out and continue. That's just my preference after many performances. Over the years, I've learned what works well and I've learned some things that doesn't work well. For example, you'll find that in a restaurant, if you approach a table and say "would you guys like to see some magic", you'll get more NO answers than you'd expect. So as a different approach, I approach a table and ask them how everone's doing. They usually think that I'm a manager or something. Then I'll just ask them if I can show them something cool. This usually works on the people who would have otherwise said NO to the magic question. Then...they always want to see more. However, there are many effective ways to approach tables in restaurants. Find which one works for you, but be sure to learn from the ones that don't.

That is a pretty good point. you don't want to seem cocky.

I use cards almost every time i perform in a restuarant. and almost anywhere else. if someone asks to show you a trick, explain to them that you are there to work, and if you allow them to show you something, you arent working, and can get in trouble with the management (this is my current out for this situation, and it has yet to fail me). This allows you to turn them down without insulting them.
One reason i like using cards is because many times when people first see you pull out a deck they think " oh god, card tricks". Which lowers expectations, and then they launch through the roof when you do something they never could have dreamed with those cards. I've found that a temporary lowering of expectations followed by a high powered, direct effect, can be a very useful strategy and can win people to your side. so thats my 2 cents. take it or leave it.

actually the managemnet employ you to help their business and to entertain the customers, if they want to show you a trick, all the better.