
When you get to the next pop up you have a few options:
-Insert only adds new records to the table
-Update will only change values on non key columns (not recommended)
-Insert or update is a combination of both
99% of the time you would only need "insert" option
If you select "Clear existing data" you should only use Insert.
You would only use Update if you know for sure there are no new CSKUs in the excel file and you just want to change the quantities.
