I might add that in the era of the streamlers, a dining car would have 5 people in the kitchen, a car steward (who seated people and accepted payments) and--generally speaking--four waiters. That's for a car wuth a dining room that seated 48 passengers. Life in a dining car was well-orchestrated chaos--but it somehow worked. The car would have to be churned pretty aggressively in order to have enough seatings to accomdoate +/- 300 people on the train per meal. Even if your plan has fewer riders, one cook and two servers ain't going to cut the mustard (pun intended!).
Mike