That is a commercial electric conveyor grill / sandwich toaster, specifically an APW Wyott AT-Express.
It appears to be a conveyor-style contact grill used in restaurants and fast-food shops for things like:
* 🍔 Burgers
* 🥪 Sandwiches
* 🌭 Hot dogs
* 🥩 Grilling meat
* Toasting/browning bread
It has top and bottom heating elements and a conveyor belt/grill rack that moves the food through the heated area.