I’m also having this problem.
I installed Tabbles a couple hours ago. I have 10-20 tags and around 5K files tagged. Using cloud.
Even after closing all Tabbles windows, tabbles.exe is eating 1.5GB RAM, same for its peak.
Resource Monitor reports no I/O from it. HD is pretty much not being used, only System is writing some data into Firefox profile files.
How much RAM should I expect ATM? Call me if I can help.