the cutting up the entire meal thread made me think about something else that i find odd (not rude, just strange). when someone takes a dinner roll and butters the entire thing and eats it like a sandwich. i was taught to take bit of butter if you're given a bread plate, and butter each piece of bread you tear off. if not given a plate, it's perfectly acceptable to put the roll on the table cloth.
the other thing that i wonder if people aren't taught anymore....when passing the salt, always pass the pepper along with it. they travel as a pair. at least i was taught they did. i'm fully prepared to admit that i was taught a lot of things wrong!