There are a ton of food options in Target Field. There are a couple of full service restaurants, including the Town Ball Tavern. See all my Target Field posts here to plan your trip to the Twins game (most posts have full menu pictures)!
When I was working at Seoul National University, I was doing some foodie research and stumbled upon this little hole in the wall place in Sillim - Endeavor Frites, which serves up Belgian-style frites and specialty beers AND HOMEMADE POTATO CHIPS!!