Let's start with the obvious. If you are sitting at a long conference table and you take a seat at one of the ends, you are positioning yourself in a place of high status. You are either telling everyone, "I'm running this meeting" or "I know a lot about this subject and want to jump in with my own thoughts." But what if you are going to run a meeting and take a seat in the middle of the table? This puts you on a little bit more equal footing. This indicates that even though you are running the meeting, you want to hear everyone's ideas and input. This also indicates that you could be mediating the meeting.
So when you sit down at your next conference table, think about the message that you want to send right off the bat.