Reposting for clarity...
Using a line of code borrowed from Jimmy Rishe's blog I can add a default number of rows to my repeating table.
I used the line for Visual Basic 2007
Public Sub ddlLocation_Changed(ByVal sender As Object, ByVal e As XmlEventArgs)
Dim x As Long
For x = 1 To 200
CurrentView.ExecuteAction(ActionType.XCollectionInsert, "XmlToEdit")
Next x
End Sub
The link to Jimmy's code is here http://www.infopathdev.com/blogs/jimmy/archive/2009/03/06/automatically-adding-rows-to-repeating-sections.aspx