In Normandy, at a formal (many courses) meal, you could signal "I'm done with this" by crossing fork and knife on the plate, handles outward, sort of 8 o'clock and 4 o'clock. Plate and flatware whisked away - and that's why so many forks etc. when you sit down. I was a student, had hardly any extra money for a fancy meal, got briefed by my flat mates who were expecting me to do something stupid-but-funny (to them, at least)