Adding external data periodically

Our external vendor sends timesheet data on their resources on a weekly basis to us. They send these as Excel files. Now, I want to consolidate them into a SmartSheet so I can create many reports for management. I tried using Data Uploader, but it needs a key column with unique data for every record in the source file to be added into the target sheet. The timesheets I get from the vendor do not have any such unique key.

The columns in the source file are:

Start date of week

End date of week

Name of resource

Name/Type of work done

Hours clocked

Is there a way to accomplish this task on a regular basis? I am looking for avoiding any manual data entry.