Hi Trent,
Thank you very much for the details!
The issue was, that that result was referring to an individual “tablepress table”, as it was selected under the post types. Tablepress uses that post type to store the table contents, but it’s not actually viewable, only embeddable in posts and pages.
To fix that, I have switched to the index table and deselected the table, as it’s going to be indexed automatically: https://i.imgur.com/1KzZk0C.png
Now searching the GH505CAA1302N part number will correctly return the parts index page, where it had been picked up from the table contents.