If you want the file to reliably persist across server calls without going back to Google to re-read it, you could use Data Tables as a temporary store by creating a media object out of the data and storing it in a media column (https://anvil.works/docs/media).
I do this when people create CSVs from other data stores for downloading but don’t necessarily do the download straight away.
I probably have an example of that somewhere if that sounds helpful.