At a formal luncheon or dinner, wait for an indication from your host before you seat yourself. The host may have a certain seating arrangement in mind.

In very formal events, there will be place holders with your name on the table to guide you.

In many cases, however, the host will either guide you to your seat personally or indicate that you may sit where you please.

Gentlemen, please remember chivalry is not yet dead! While the ladies may not give you condemning looks, they will appreciate it if you wait for them to be seated before you sit.