Hi oldhasbeen,
Thanks for posting in our forum. For your problem, I suggest you try to clear the caches of Teams and see if there is any improvement:
Go to %appdata%\Microsoft\teams Then delete the following files. As a side note, you can move the files to another place to avoid the data loss.
a. In Application Cache > Cache folder, delete all files in it.
b. In Blob_storage folder, delete all files.
c. In Cache folder, delete all files.
d. In databases folder, delete all files.
e. In GPUCache folder, delete all files.
f. In IndexedDB folder, delete the .db file.
g. In Local Storage folder, delete all files.
h. In tmp folder, delete all files.
If the issue persists, we suggest you vote for the feedback below via the following link. There is no option in Teams to reduce the memory usage.
https://microsoftteams.uservoice.com/forums/555103-public/suggestions/33643924-reduce-memory-usage
Many features of current programs have been designed and upgraded based on customers’ feedback.
Best Regards,
Huni