Updated my first post. I've noticed this as well. Hopefully the memory leak is solved in the coming weeks (or days)!
Fighting, trading, went into town 'n bought a brewery, more fighting, went to a keep and played a board-game.
Great news that you are on it! The memory leak is still here sadly:
As problemsolver said. 8 GB ram is simply not enough right now, but once this issue is fixed you should be good with 8 GB.
Intel processors seem to have some issues running the game, if you're using one that could be why..
So far I've only been able to solve it by restarting before 90% of my RAM is used. After that point the page file starts being used. I'd love to hear if anyone have another suggestion.
Thanks I'll add the tag (edit: dosen't seem to be possible, I'll edit my post i stead). You can reference to images or this posts, that is okay!
We came to the same conclusion then (read page 19 in media)