I am guessing here, so please correct me if I am wrong (read: when I am inevitably wrong). En tavla is something that has a frame, including 'a blackboard', whereas en målning is canvas, or something similar, with paint on it.
I’ve never thought about it that way but it sounds correct. Note that en målning can have a frame and still be a målning however, it doesn’t have to be either or. It can be both.
Blackbord = "Tafel" in german. For painting I would prefer the word "målning". I mean "tavla" is not just a painting, it is also a picture. A "tavla" is a little bit more general. And "En tavla" from a modern artist is often not a painting, it is not painted. But perhaps this is not the place to discuss about art.
Nevertheless, Swedes often talk about paintings as tavla. I am much more likely to say that there is a tavla on the wall than målning when talking about a painting.
It's the same word! Both are derived from Latin tabula. :) And the Turkish version of backgammon is actually called "tavla" in English as well.
Almost. Tavla is right. Tävla means "to compete", while a contest or a competition is "en tävling"