My parents have a habit, at restaurants they go to often, of not ordering everything at the beginning when the server asks. For example, they love a particular Chinese restaurant and go there at least once a month. They will order their drinks and appetizer/soup, and then after they have finished the soup they will order their entree.
This makes sense at this particular restaurant because Chinese food is prepared very quickly, and we know from experience that if we order everythign at once, they will deliver it all at once.
They do this at other restaurants, too, when they've learned from experience that the food is delivered too quickly.
Granted, this is the fault of the restaurant. Food should not be brought out until the previous course is finished, unless only one person isn't finished and they're taking way too long. But rather than stop going to a place they love when the staff doesn't seem to want to change, my parents change THEIR habits. It does come off as pretty rude sometimes, though.
Does anyone else do this?