Olde Hansa is a medieval theme restaurant set on three floors of an ancient building in the old town of Tallinn. With the staff in costume and acting in period , candlelight and the menu to match it is aimed at the tourists and could be just terrible. What saves it is that the staff are so friendly and enthusiastic about what they do, and that actually the food is rather good. It is authentic feeling food, well prepared and tasty and gives you a chance to try game and rabbit, even bear.
Personally, I am not sure it really works for couples, but I can see that it would be a lot of fun if there was a group of you, especially if you had a few drinks first. Two courses plus beer for the two of us came to €70 so it isn't horribly expensive.