Keep your mouth closed when chewing. Do not be the first person to take your jacket off during a meal. Keep your elbows at your sides and off the table. Push your chair in when leaving the table. Make the effort to introduce yourself to everybody with talking distance of you at the table, and to direct questions to them to help get them involved with any conversation.
Cocktail parties are a whole different affair than the seated meal.
The risks of losing control or being indiscreet are too great. In fact, be sure to pace your alcoholic intake throughout the course of the evening so you will not reveal your company's secrets, or tell a client's spouse what you really think of her or him. At the bar or food station get what you want and move away. First of all, the right hand should always be kept free to shake hands with any man or women. Food, drink, napkin, - everything goes in the left hand.