Thanks a lot, Johnny! When I calculate the ratio of passenger seat per dining car seat, I note the ratio of some popular overnight all-coach trains like my favorite one the PRR Trail Blazer of 1938, was 572 coach seat : 66 diner seat, which was around 9:1 (standard 14-car consist) if the train was full.
Assuming dinner was available since 6 pm and all passenger wanted to have dinner in the dining car and each passenger requires at least one hour to finish their dinner, some passenger might need to wait until 1-2 am for a table! But of course, there was a lounge car provide a light meal for them and not all passenger wanted to use any service of the dining car…