I've made two multi-day round trips this year traveling alone. Both with multiple LD trains involved, so quite a few meals. If I'm in a chipper mood, I've gone to the diner ready for whatever seating I'm given. A couple times I was in a quieter mood, and went to the diner kind of hoping to be seated alone and ending up seated with others anyway. Each time I was seated with others, I ended up having very interesting, intellegent, enjoyable conversations that added quite positively to my vacation experience. I had a couple meals in my room and there was no salt & pepper, no drink refills, just not very convenient. Maybe I've just been lucky, but with only one exception, I've found my fellow Amtrak travelers in the station lounges and on the trains to be fun & interesting additions to my adventures.