Yep, I have one with a multicart with almost every game for the Vectrex on it that I purchased probably close to 20 years ago... don't think I've used it in 15 years though. No telling if the guy that made the cartridge is around anymore. I can take a look at it when I get home and tell you the name of the cartridge if that's something you'd care about.
Ok, just looked at mine. It's a Sean Kelly multi cartridge. Has 60 games on it... pretty much all of them. If you look around the internet you should be able to find one. That's the only way to go. He used to sell overlays for the games as well, which I bought back in the day. Not a necessity, but it makes some of the games much cooler looking.