Yes, you can bring food on Amtrak trains that you can eat at your seat or in a lounge or café car. We encourage bringing food on board, including to-go meals from restaurants near stations, if you have special diet needs, like to eat large amounts of fresh fruit and vegetables or don’t want to purchase food in the café or dining car (note that meals are included if you book sleeping accommodations). A small cooler can count as one of your carry-on items if you need to keep anything refrigerated.
Alcohol can also be brought on board if you have private sleeping accommodations, as that is the only place you can consume it, and not publicly in coach seating.
Amtrak Guide 