People will put their elbow on the table, rest their head in it, or cross their hands. That's OK in a very relaxed setting, like at home, or at a barbecue or at a café, but in a good restaurant, or at a formal business meal, you should sit straight in your chair, and keep your hands on the table. This is actually a habit that is hard to break: when I lived in the US, I was invited for Thanksgiving to the mother of a friend's house. Of course, I wanted to show off my good side, and be polite, so tried to keep my hands on my laps to conform to the American code of table manners. Each time I used my fork and knife, or drank, my hands went back on the table...I'd realize it and put them back on my laps. And then they'd go up on the table again... It must have been fun watching me doing this little hand dance all afternoon long!
You will find more table manner tips like this one in my lesson French Table and Hosting Etiquette.

