Gueridon Service is a term used in the restaurant business to refer to "trolley service." Food is cooked, finished or presented to the guest at a table, from a moveable trolley.
Dishes typically served like this include Crepes Suzette, Caesar Salad, Cherries Jubilee, Banana Flambé and Steak Tartar.
There are several reasons for Gueridon Service:
ensures exact serving temperature and stage for any dishes sensitive to this;
turns food into entertainment;
creates an atmosphere of sophistication;
stimulate demands in other guests for that level of attention.
The food being served is usually partially or mostly prepared in the kitchen -- certainly any prep work such as chopping onions, actually cooking crêpes, etc, is done there. The waiter then does the final assembly or cooking on the trolley at the side of the restaurant customer's table. This might involve flambéing an item, or carving it, or tossing a salad.
The trolley is equipped with a burner for cooking, that can be powered by gas, electricity or spirits. Some trolleys will have a cold drawer as well. All will have a chopping board and cutlery drawer, and be equipped with the necessary utensils for what the restaurant offers from the trolley. There will also be on the trolley a selection of basic condiments such as mustards, Worcestershire sauce, oil, vinegar, etc.
Gueridon Service is less popular now. For it to be practical, restaurant dining rooms have to be less crowded with tables than many are now, to allow enough space between tables for the trolley to move and be positioned. Additionally, dining room staff need to be specially trained in how to finish the dishes being offered.
It may also be that restaurant customers got bored with the same typical dishes that were offered, as those dishes lost their novelty over time.