I remember taking the train home from Fargo, and the dining car only had plastic dishes, but that was because (I'm pretty sure, at any rate) because the water pipes had frozen up - it was about -25F.

The trains I took to D.C. (Mpls to Chicago, the Chicago to Washington) all had "proper" plates, silverware, and tablecloths.

Sigh, I gotta do more train travel.