"when I protect the document, the table is no longer editable"
That's how Word works. So that's not a bug so what do you want to do next?
Here's my thought about some Office automation tools. Sometimes you find people trying to make a template to avoid writing an Application.
I am trying to create a template with text boxes that automatically adjust their size to the amount of text placed in the box. I cannot seem get the text box to automatically become multi line. If I insert a table, it works, but when I protect the document, the table is no longer editable. If I could make the text boxes relative it seems the problem would be solved, but this is not an active selection in properties.