When designing a new form select SharePoint List as the template.
It will prompt you for a Site Location and then a name for the list.
On the last setup page begore hitting Finish select "Manage Multiple List Items with this form" It is in the Advanced Options.
You can now create a data connection to the location for your lookup. Create the fields in your repeating source to input the information for that user. The user can then hit Next Entry or whatever you have designated for it to say for the next entry. Then at the End configure a Submit button and then it will submit them all to the SharePoint List as a separate entry.