Log in as admin
Go to "Spam" page, i.e. https://test.archiveofourown.org/admin/spam
For the listed works, check "Confirm As Spam" for some and "Mark As Not Spam" for others
Press "Update Works"
Go to "Activities" page, i.e. https://test.archiveofourown.org/admin/activities
The changes to these works are not listed.
What should happen
The changes should be listed with the action described as either "bulk mark as spam" or "bulk mark as not spam" as appropriate.
Testing this will require someone with database access to make works appear on the Spam page.