The person who invented the banquet table, the round table for ten, wasn’t doing it to please those at the banquet or even the banquet organizer. He did it because this is the perfect size for the kitchen and the servers. The table for ten is a platonic ideal of the intersection of the geometry of bread baskets, flower arrangements and salad dressing. Bigger and you couldn’t reach, smaller and there’s no room.
But, here’s the thing: the table for ten isolates everyone at it. You can’t talk to your left without ignoring your right, and you can’t talk across the table without yelling. And so, the very thing you’ve set up to engage the audience actually does the opposite. This is even true if you're taking nine people out for dinner–ten at a table undermines what you set out to do.
Worse, if you’re brave enough to have a speaker or a presentation at your banquet, you’ve totally undermined your goals. Half the audience is looking in the wrong direction, and there are huge circles of empty white space that no microphone can overcome.
In my experience–I’m sharing a hugely valuable secret here–you score a big win when you put five people at tables for four instead. Five people, that magical prime number, pushes everyone to talk to everyone. The close proximity makes it more difficult to find a place for the bread basket, but far, far easier for people to actually do what they came to do, which is connect with one another.
Thousands of speeches later, I can tell you that the single worst thing an organizer can do to her event is sit people at tables for ten.
If you want to let the banquet manager run your next event, by all means, feel free. Just understand that his goals are different from yours.