Don't chew with your mouth open.
Don't put your elbows on the table.
Don't belch in public. If you do burp, say, "Excuse me."
Bring the food to your mouth, not your mouth to the food.
Don't pick your nose.
Have you ever asked yourself what is the point of manners?
They don't really do anything. Not anything important anyway. It's not like The Ten Commandments or the Amendments of the Constitution. No one is going to get hurt or die if you put your elbows on the table. Is there really a point to knowing which side of the plate the fork goes on?