Only after going on lots of dinner dates with lots of different people, friends and more-than-friends, have I truly gotten the scope of table manners. I think there are a lot of rules for dining that we can throw out the window at this point. Take a look at these rules of etiquette from 1940:

http://www.oldandsold.com/articles05/business-6.shtml

It says a formal dinner should not begin before 7 o'clock... well I get hungry before 7pm, and besides, all the diet books tell you not to eat too late. So let's toss that one.

Don't be late. I like that one. As a cook, I know it's frustrating to have the food hot and have someone arrive late. However, if you're inviting over a friend who is usually late... I suggest you make chilled food that can sit pleasantly on the table until their belated arrival.

Then there are all these gender rules about who holds whose arm when and on what side... Although I do enjoy a chair pulled out for me every now and then, I think we can safely say that left/right man/woman tactics are sort of passe. So just play along with your companion to make them comfortable. (The best manners you can have are thoughtfulness about the other person's comfort.)

When ordering food, I do think the most senior lady goes first, followed by the rest of the ladies, then the gentlemen. I don't know why I like that so much. I just generally like ladies first.

Napkins on the lap are a GOOD thing. They take up room on the table and they protect your lap. That's just common sense.

Knives should sit on the top edge of the plate so they don't soil the tablecloth. Chew with your mouth closed! Don't talk while you have food in your mouth! Don't take the last bite! Anything else?