Heya Jason
Thanks for answering. I'm using the newest LB non-beta 9.9 version with box view. It only started appearing when I added screenshots to games. Once I click on a few with the game details tab on it starts to add up very quickly. The RAM usage does not normalise if I disable the details tab.
Also, I just realised that if I start LB without the details tab and if no screenshots ever get loaded that way, the RAM usage stays at <1GB. So I think it might be an issue with the details tab. So for now the workaround is not to use the details tab or to close LB after every launch.
I can upload my whole LB folder (9GB) to Mega.nz if you'd like...
I'm using W10 1809, 16GB RAM, 7700k, 1080Ti
Let me know if you need more.