Is there a plugin or scrypt on saving track number totals with an album?
If I’ve understood you correctly, I think Picard already does this automatically?
“Total Tracks” is set right at the bottom of the ‘tag’ window in Picard 
Or are you after something else?
Sorry I am terrible at describing myself. On the left hand side, you can cluster your albums for the ones you don’t feel like adding to the database (site). Is there a way to put the total track numbers in without doing it manually?
Not that I know sorry.