Hello Matthew.

I am sorry to disappoint you, but unfortunately something like this is not possible with the plugin's built-in features.

This could only be done if you install a membership plugin, where you can define certain pages that are password protected. But even in that case, you would allow access to a page, and if you set the manual table to be editable, it will be. You can also define user roles in Editing tab above the table, so only certain user roles can edit the table.