I replaced the fuel pump in an Audi 5000 once and found the fuel pot to be just that. It looked like a steel frying pan with higher than normal sides.

Nothing special about it. It is just the place where the fuel pump sits to suck gas, but it would be harder to empty it with a hard turn.

And.... If there is something in your tank that should not be there, like dirt or scale, you would only suck up what was in the pot area and not from the entire floor of the tank. Since the sides are so high and crud normally falls to the bottom and stays there it can swirl around on the bottom and never get into the pot where it could clog the pick-up screen.