The food on board is basic cafeteria food, but there are a lot of options both hot and cold for all three meals a day. Prices are moderate. There is no restriction on bringing your own food and beverages. Passengers who want a lot of on-board entertainment also won't find it on the ferries. There are lectures provided by U.S. Forest Service staff on the ecology and history of the Inside Passage and its ports, TV lounges, an on-board movie offering and a few video games.
Most ships have a bar, with a piano.
The scenery of the Inside Passage, the company of my fellow travelers, and a good book were all I wanted. But passengers who want dancing, music, gambling and so on will be disappointed. Travelers are also expected to plan their own itineraries in port. That's great for independent travelers but won't work for folks who want a pre-planned guided vacation package. Tourism offices can help.