Wow, I'm sad to say that I'm not surprised this is considered "normal" for any software. 500MB is a lot of memory to be hogging for a text app that isn't even being used. I have no idea what it could be doing in the background like that, even if I am using the Chrome Extension. Maybe I need to be more diligent in shutting down web pages, but when I do research I often leave many tabs open for a while, even after clipping them. Maybe this is what is causing the issue. Still I don't see why the processes can't shut down after I've clicked "clip." Now my RAM usage is doubled because Chrome is using RAM to keep them open too. It's a good thing I have 64GB.
Whenever I decide to switch gears and do audio or video I'll just have to go through a process of closing all my browser windows and processes in order to make sure nothing happens while I'm recording, editing or rendering. That's just the nature of wanting to do everything on one computer.