from show off my bakery thread:
[velvetychocolate's place, top of page 171 on that thread]
this is a feeding pen layout. since all the chairs are only a few steps from a door/cash register (and customers can't leave the area next to the door they enter, all exit routes are blocked) they can only walk a few steps before it's time to sit down and eat. the amount of time it takes them to actually eat is always the same, but these customers will spend a lot less time walking, meaning you'll be able to cycle the 28 customers more quickly, meaning you'll sell faster.
there are other layouts, a lot of it is based on the number of doors you have, but the principle remains the same.