ManicPot8to Several Innisgreen lots have been triggering crashes, perhaps all of them in Sprucederry and at least a couple in the one in the top left. If you'd like to provide a lastcrash generated while playing anywhere in Innisgreen, I can pass it along. Make sure it was generated with no mods or custom content present. The file would be in Documents > Electronic Arts > The Sims 4, and if you want to attach it to a reply, you'll need to delete its first line of text.
If you post a lastcrash, please also attach a fresh dxdiag to that post so that I can link just the one reply.
As for the high RAM usage elsewhere, the game has been getting a lot of performance adjustments lately. I'm not sure whether this is a mistake or an intended part of that ongoing process. After all, more assets loaded into memory means less of a delay in retrieving that info where necessary, and if your computer has the RAM to spare, it's not necessarily a bad thing to use more of it. But that doesn't mean the current implementation is the most helpful. And I'm reasonably sure this isn't the end of the process either.