Thanks for noticing this and letting us know about this!
The short explanation:
The quoted close texts on the help page you've pointed out are intended to be representative reasons and explanations, not strictly necessarily those that are seen on the specific site you're on.
Why not just use the actual texts for our site?
Because many of the pages in the ...
This is a known bug
If you have text right above or below the table, the preview renders the table markdown as a table. But after you save the post, the table is not rendered and just shows the markdown code.
The rest of that answer is a demonstration of the bug.