Using mail merge to complete customer update form

I have been cracking my head to merge customer update form with
existing data. Example as follows:

Excel rows contains the following information:

Customer number, customer name, business purpose (billing or
delivery), contact, email, address

What I would like to do is to merge the above data in the customer
update form (MS Word). The problem I have is that I have multiple
customer with similar customer number and name but different business
purpose, contact, email and address.

Can anyone out there help me?

Thanks.