I think it was Emmerdale where two actors/actresses are sitting in a diner with the food going round and round. I have never been to one of those. What is it and how do you pick your food???? etc
As ummmm says,
They are on a conveyor belt.
Usually you have a menu to guide you (by picture) as to what the sushi is,or it has little sticker under the clear plastic lid.
The bottom bowls of the sushi are different colours,which correspond to the price of the sushi.
When you have finished the cashier will total up your bill from the number/colour of your bowls.
Or it could have been a "Lazy Susan" a large revolving tray on which the various parts of a meal are placed,with the diners spinning it and helping themselves you often see them in Chinese restaurants when a party orders multiple dishes