Tons of stuff to do at that situation. I'd do glass/salt shaker thru table like many more. Bending silverware tricks if doable. Depending on silverware.

Vanish a coin, and find it in a piece of bread. Some mentalism effects if I just have a pen. I could do a torn and restored napkin if it ain't made of cloth. There is so much.. I have a ton of impromptu dinner table magic tricks in my head hehe..

There is a pretty decent dvd from the "World's greatest magic" series, called "Dinner table magic". There you got David Roth as mentioned doing some really nice coin routines.

Ronnie

I also like coin thru drinking glass.

I just don't venture into public without a deck of cards, and I know so many impromptu card tricks that I don't know them all anymore haha, seriously though when I do restaurant gigs my entire routine is with a normal shuffled deck, if it's good enough to get paid for, it's good enough for those "show me a trick" moments lol

And yet I failed to tell you what I actually do, I start with a trick I don't know the name of, where they pick a card, and then take another card and push it into the deck, after failing to find their card that way it turns out to be the card in their hand, I follow that up with a 2-4 card selection, having one card that I "messed up" turn into all of the selected cards. then I do my ACR ending with card to pocket.