Here's what my parents did to distract me when we were waiting in a restaurant:
There's the classic "catepillar" where you bunch up the paper from a straw, and when you add a drop or two of soda, the mashed up tube of paper grows lengthwise as if it were growing/moving.
Then there's the ever popular trick of getting an octagonal salt-shaker to stand balanced on one of the eight edges on the bottom. The trick is to add a small amount of salt to the table, and trying to balance the salt-shaker in the salt. It sounds impossible, but it works. Then you time it to see how long it takes for it to fall over. My personal record is 20 minutes.