In Outlook 2002, how can I create a custom Outlook form template (.oft) file that lets me display HTML tables in the body of an email message?

You can use Microsoft Word as an email editor (WordMail) to create complex messages with tables and other HTML elements, but the Word editor doesn't let you save such messages as .oft files. To work around this limitation, use WordMail to create the message, then save the message and close it to store it in the Drafts folder. Choose Tools, Options, Mail Format, and clear the Use Word to edit e-mail messages check box. Open the item you saved in Drafts, and you'll see the file in the regular Outlook editor. Choose File, Save As to save it as an .oft file.

I recommend that you consider whether you really need to use an .oft file. These templates are useful if you need to share a custom form with someone outside your Exchange organization, but for internal use, you're often better off publishing the form in a public folder.