Well, Alex Cornell has given us some tips on choosing the right seat. Check out his infographic and explanation:
One of the most complex social situations you will encounter is the 45 seconds that elapse while deciding where to sit for dinner at a restaurant. Your choice should appear natural, unbiased and haphazard if executed properly. Timing is everything.
These 45 seconds determine how enjoyable your next 2 hours will be. Once the pieces start to fall into place and people take their seats, your choices narrow. People sit, seemingly at random, and if you don't take the appropriate measures, you're inevitably stuck at the least interesting end of the table.
4 Person Circle: This is the ideal setup. You are safe sitting in any seat. Regardless how interesting everyone is, you pretty much can’t go wrong. Note: as the diameter of the table increases, so too does the importance that you sit adjacent to someone you like.
4 Person Square: This configuration (as opposed to two chairs on each side) is less fraught with problems. Something to watch out for is diagonal conversations, i.e. breaking the into two parts and getting stuck with the more boring of the three tablemates.
6 Person Circle: How loud the restaurant is determines how important it is that you claim a middle seat. A quiet space allows for cross-table diagnoal talking, and generally one conversation. A loud space however forces multiple conversations and less diagonal.
8 Person Rectangle: To get one of the interior 4 seats, you need to time your approach expertly. You can’t be first, else you’ll be expected to file to the end. And you can’t be last, else you’ll be stuck with the least interesting seat at the table. Timing is everything.
7 Person Rectangle: It’s very easy to get screwed in this scenario. While it may appear like you can sit anywhere except the ends, this is not so. You are at risk of sitting next to the lonely end-seat, which requires you to speak soley to that person for the duration of the meal.
2 Tables of Any Size: You’re fucked. Regardless of how you time your approach, you will inevitably choose too soon. Lament as the other table’s attendance crystallizes into what is clearly the superior group. Sometimes it’s best to visit the bathroom while seats are chosen, so any seating disasters are the result of chance, and not your own miscalculation.