I know that there is such a thing as HTML mail, but I stay away from it and I hate emailing spreadsheets around, so I'll just give you some food for alternate thought.
I apologize in advance if your particular situation rules out something like this:
Publish tables to a website and send the report recipients a link. Since most people will end up ignoring your email anyway, you'll save a lot of resources in your email system and newer recipients will have the archive of past reports easily available.