Export MS Word HTML into valid, XHTML table?

We have employees in another department who post data to our website via an online form we'd set up for them.  The form automatically generates basic HTML (paragraph tags, bold tags, italics, etc.).

The employees often want to post long HTML tables that they'd generated in MS Word.  Unfortunately, if we ask these employees to save these as an HTML file, MS Word generates some pretty hideous code and many unnecessary, Microsoft-specific tags.  Usually the ending code is so large that it crashes our online form, since online forms have a maximum byte amount they can pass at any given time (no joke, these tables are often quite huge).

Is there any tool out there that can parse MS Word-generated table data and recreate a table into tight, XHTML format?  We're trying to avoid the time necessary to program our own robust, MS Word HTML parser, since this is such a low priority item (but not so low that the subject of doing this comes up once every year)