I have autovacuum globally enabled, sql query:
select * from pg_settings where category like 'Autovacuum'
shows that autovacuum setting is "on".
Does that mean all tables in the database will be subjected to autovacuum periodically, or I need to additionally set autovacuum to "on" individually for every table in order to autovacuum it?
Yes, that means it's globally enabled.
You don't need to turn on manually for each table.