Frankie & Benny's or TGI Fridays would probably be the closest in more recent decades, especially the fact that they had a bar and were very much for the office worker crowd back when I remember them being big / new.

Most of ours are roadside places really, but none fit exactly. Little Chef was probably the most like it in terms of not having a 'theme', but the kinds of food and cheaper vibe was more like Happy Eater's maybe, with the buffet counters and salad bar etc.

(For any non-Brits go look up Happy Eater restaurants. The logo was a Pacman seemingly trying to make itself throw up, I shit you not)