MIME::Lite is a fairly low level module for creating e-mails that are MIME encoded. That means that, in addition to attachments, you can have the e-mail body be something other than plain text. If you want to send e-mails that are formatted, you're going to want to create an HTML e-mail. This is where you're going to have to do more than simply copy and paste in a MS Office appliction - you're going to need to do the equivalent of pasting your table into something (possibly Word) and save that as HTML. You'll then need to take the HTML table code and put it into the body of your e-mail. You're then going to have to write Perl code that sets the HTML for your e-mail body, for your table, and for any other information that you want in the e-mail. One very good HTML authoring site is SitePoint.com. They have an excellent guide on how to create good e-mail newsletters. Although you're not specifically creating a newsletter, the information still applies, because you're creating an HTML e-mail.
PS: Even though I mention Word as a possible HTML creator, I only say that because it sounds like you have not written Perl code to generate e-mails before. Word's HTML formatting is complex, verbose, and from an HTML standards perspective quite bad.