The Oak Tree is truly a diamond in the rough. Kind of a hole in the wall place that seats maybe 50 or so, however, they have some of the best food in Jackson. Every day, they offer a variety of home made soups. And I'm not talking about one or two, its like six, and they're all very unique (i.e. Reuben chowder). I haven't had one that wasn't excellent.
The Upper Deck and Lower Deck sandwiches are amazing club sandwiches (only order the upper deck if you brought your hungry-man appetite). Voodoo chicken is another winner. The burgers are amazing as well - again, bring your appetite, cuz their huge! The Cajun burger is my fave, but its only offered as a special so keep your eyes peeled for this on the chalk board.
I would categorize the Oak Tree as gourmet bar food with a home made twist that will knock your socks off. The staff is super friendly and always ready to give you a candid and honest suggestion.