Automat

People from all levels of society ate in Automats at least occasionally. Movies often cast their cosmopolitan stars dropping coins in Horn & Hardart's slots, and tourists felt compelled to visit an Automat.

Source: wiktionary

The Automat, whose gleaming chrome-and-glass machines brought high-tech eating to a low-tech era, has gulped down its last coin and served up its last helping of macaroni, baked beans and kaiser rolls. The last Automat in the country, in midtown Manhattan, closed on Tuesday, a victim of changing eating habits. […] There were 30 Automats in New York when Mr. Stern was a young Western Union bicycle messenger stopping in for lemon meringue pie between deliveries.

Source: wiktionary

While automats were hailed by the thrifty populace as being “waiter-free” and—even more appealing—“tip-free,” someone had to cook the food, stock the little compartments, keep the floors clean, bus the tables, refill the sugar and condiments, and exchange larger coinage into nickels, since patrons rarely entered with enough nickels for a meal.

Source: wiktionary

When King George sat down in Perylon Hall he thrust his gray topper under the chair, just as you do when you're in the Automat.

Source: wiktionary