Supabase developer here.

I've used this to move data from a live Supabase database down to the browser for testing and playing around with things in a "sandbox" environment. Then I save snapshots along the way in case I mess things up.

To move a table over from my Supabase-hosted postgres instance to the browser, I just exit out of psql and run something like this:

pg_dump --clean --if-exists --quote-all-identifiers -t my_table -h db.xxxxx.supabase.co -U postgres | psql -U postgres

Keep in mind if you try something like this, our proxy is rate limited for now to prevent abuse, so it might not be super fast. It's easy to remove rate limiting at the proxy, though.