To do this with Word's mailmerge tools, you would need to use three separate mailmerges, then combine the output documents. Even for that, though, your document isn't properly configured for handling variable amounts of data. To do that, you'd need to use Word's Catalogue/Directory Mailmerge facility (the terminology depends on the Word version). To see how to do so with any mailmerge data source supported by Word, check out my Microsoft Word Catalogue/Directory Mailmerge Tutorial at:
http://windowssecrets.com/forums/sho...merge-Tutorial
or:
http://www.gmayor.com/Zips/Catalogue%20Mailmerge.zip
The tutorial covers everything from list creation to the insertion & calculation of values in multi-record tables in letters. Do read the tutorial before trying to use the mailmerge document included with it.

For some worked examples, see the attachments to the posts at:
https://www.msofficeforums.com/mail-...html#post23345
https://www.msofficeforums.com/mail-...html#post30327
http://windowssecrets.com/forums/sho...l=1#post928391

Alternatively, you may want to try one of the Many-to-One Mail Merge add-ins, from:
Graham Mayor at http://www.gmayor.com/ManyToOne.htm; or
Doug Robbins at http://bit.ly/1hduSCB

In addition to a 'Many to One' merge, the latter handles:
• Merge with Charts
• Duplex Merge
• Merge with FormFields
• Merge with Attachments
• Merge to Individual Documents
• Merge, Print and Staple

Rather than using a mailmerge, however, I'd be inclined to use three database fields for this. Doing so obviates the need to generate the three separate documents and means the document can auto-update any time you open it. Without knowing more about your data source and reporting requirements, I can't give more specific advice, however. If you could you attach a workbook to a post with some representative data (delete/obfuscate anything sensitive), I'll have a go at setting this up for you.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]