I have seen lots and lots of different uses for Excel in my line of work:

- password database - script to automatically rename jpeg files - game - grocery lists - Book keeping (and try and not get caught for fraud several years, because the monthly spending limit is $5000 and $4999 a month is below that...) - embed/collect lots of Word documents - coloring book - Minecraft processes - Resume database - ID scans

I've seen it used for laser testing. Not tracking test results. Testing lasers.