One phrase commonly used in 1946 is "one-arm" restaurants. As the website "Restaurant-ing Through History" explains the term went back to the turn of the last century when many fast food lunch joints introduced chairs with sidearms for solitary diners, who previously ate standing up at the counter. Like the seating in the fast food places of today, the seating was deliberately uncomfortable to discourage lingering. It was meant for the in-and-out, quick bite crowd of office workers, generally males, and the fare was basic and cheap. Usually you ordered at a counter, although some had waiters.
These restaurants occupied narrow storefronts in commercial districts and the seating was in a row along one wall with the counter on the other. As women increasingly joined the work force in the 1920s, tables and chairs replaced the side arms to make them more appealing. They still exist in large number in the business districts of Manhattan and other large cities, where takeout is often the norm, although the term is no longer commonly used. Usually we call them luncheonettes or something else. Essentially they were the bottom of the restaurant hierarchy before McDonald's and the like came along. The Waldorf Cafeteria was a widespread chain.