This is the Magnavox Odyssey TV, model 4305. As far as I know, it just had their version of Pong in it, but it *switched* from a TV to a game without having to get the console!
It even came with its own special controllers apparently. Pretty neat stuff from the 70s, I can't recall any other TV that would have video games built in. It also was quite rare from the sites I read about it.
