Back in the day, the Northeast trains did have full dining service. In the summer of 1975 I was a regular passenger on the Bankers, WAS TO BOS. I rode from PHL to NYP. It had a diner, and I was able to get served a full dinner between Trenton and Newark. I seem to remember they did a good business. Streamlined service - choice of fish, chicken or steak, prixe-fix with 2 veg, salad and roll. You filled out your order, all the waiter had to do was take your check, bring your food, and collect the money. It should work even better today, what with preplated. meals, but I think the eating public today wants more menu choices, which complicates things.