Deleting Non-Matching Records when Importing Excel File

I have a table that is filled with the data for all users in a particular system.
That system comes from another department, and they provide me with that user data in the form of an Excel file (we're talking over 6,000 users, for context)
The issue is that users leave, and so their "line" in the provided Excel file also leaves.
Is there a way that, when I upload the Excel file to my existing table, if an existing table record isn't matched to an Excel line, the table record gets deleted?
I could just wipe the table of all its data periodically and upload fresh, but I'm hoping there's an easier way.
Thank you in advance.

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Graham Haskin
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