RDM v11.7.6.0 64bit using 8+ GB of memory

My RDM v11.7.6.0 running on Windows 10 is using a lot of memory. I've seen it use 8 GB with only 15 sessions running. That seems like a lot.
I suspect some of the Web Pages I am loading are using a lot of the memory. Example:

Is this a known problem? Should I try another OS? Should I be using RDM 32bit instead?
RDM has not crashed but I get nervous when any app uses that much memory.
Note - The links I am using above are links to Microsoft Office 2016 One Note pages. I tried using the dedicated One Note option in RDM but it does not work... The URL is not parsed correctly. The front-end of the URL is dropped for some reason. Separate problem.