If you're train is a morning train, you will be offered a pastry (there are multiple) and a drink.
Later on, you will be offered snack box shown below (the drink is one I bought prior to boarding, not offered on board) along with a drink. Only one snack box is offered per trip. If you're attendant is nice I'm sure they will let you have another.
You can ask for another drink later on as well. You get one food item and drink per person.
The snack box has quite a few things it it, all listed below. I found them all to be good.
-Perky Jerky (Turkey)
-Bart and Judy's Cookies (Chocolate Chip)
-Santa Barbara trail Mix
-Crunchmaster Multi-Grain Crackers (Sea Salt)
-Stella's Snacks; Petite Pretzels
The drinks are standard, juices, water, sodas. Not sure about hot drinks, I don't drink coffee (love the smell though). They also include a small bottle of white or red wine, complimentary.