> Hi, is there a way to vacuum or reorganise tables?

Reclaiming unused spaced is done automatically by the "Garbage
collection". This is the same thing that "VACUUM" on an PostgreSQL
database does perform.

> The only way I know of doing it is to do a backup restore?

If you intend to give unused space back to the operating system an
Backup/Restore is the only way to do so.

Elmar