I think the information about which editor is associated with a given page or post is stored in the wp_postmeta table in the WordPress database. The wp_postmeta table stores metadata about posts and pages, including the author, the editor, the last modified timestamp, and other essential/related information.
The specific row/meta_key that stores the editor information is called _edit_last
This metakey actually stores the username of the user who last edited the post or page.
Ah, OK I see it now. Thanks!