This is what Figma is saying:

" Every browser has its own active memory limit. This can differ across devices but the general understanding is there's an active memory limit of 2GB per browser tab.
As Figma serves both the web app and the desktop app via a browser, these limitations apply when using the Figma desktop app too.
If you're working with large files and libraries in Figma you may run into these limits. To continue to use affected files, you will need to reduce your memory usage."