Hi @titsmaker
The ActionScheduler entries are not regular post types, they are scheduled actions (https://actionscheduler.org/). And the same kind of actions that creates WooCommerce for internal tasks and you can see if you go to:
WooCommerce Status >> Scheduled Actions
That said, those actions only can be able to run if the plugin is still present (as the code that tries to run resides on ATUM). So it’s very weird that one of the actions that are shown in your screenshot was completed (instead of failed) if ATUM was not installed on your system on the 18th of October…
But if you uninstalled the plugin after that date and those are the only records you have there, then it’s just a log (not created by ATUM but by a dependency) and you can get rid of them manually.
Also, regarding the atum meta key you have on your products. I’m not sure why this remains there as we are not using meta keys since long time ago (since we moved to our own custom tables). But if you want to get rid of all at once. Just browse your database with any DBMS (like PHPmyAdmin) and run this SQL query:
DELETE FROM wp_postmeta WHERE meta_key LIKE '_atum_%';
I hope this helps.
Best Regards,
Salva.