As Caeli said, how about smallish, but with all the shops we need? Even a  small, quiet country town should have a train station., restaurant of some sort, snack bar, supermarket, hot spring etc. etc. If it's too tiny, a tram service and train station would seem slightly out of place. I think the current map is fine, with the addition of a few shops and perhaps a few more houses. 200m x 200m seems a bit on the titchy side, but 300m x 300m should be big enough. We can imagine the scale as we see fit though, so as long as everything's there, the map you've so professionally drawn will do nicely.