How to Model Flat Invoice Records in Excel File

Hello All:

I have a situation that is a first for me.  I downloaded an Invoice file as Excel File, and each invoice is showing as one row, with the billing line items (SKU#, Qty, Unit Price, Line Total) is showing as columns.   As such, each invoice varies in terms of the number of columns. Could someone help me to create a Monarch Model for such Excel file, to write meaningful reports against the data.

I have been successful trapping such text/pdf reports, but never encountered Excel files like this before.

Many thanks in advance.

Al Rice