lunchroom

A luncheonette.

A room in a facility, such as a school, in which lunches may be purchased or those brought from home may be eaten.

a dining room (in a school, business, or other non-domestic facility) where lunch can be purchased.

A room reserved for eating food, especially at a business (lunch may or may not be served there).

A diner or restaurant that specializes in serving lunch.

a restaurant (in a facility) where lunch can be purchased