No, it won't become inefficient. Generally you're simply overwriting the old
information with the new.

One recommendation: if these work notes are crucial to your business or work
process in general, in other words if you consider them very important; then
be sure you make a backup of that file regularaly. The backup should be to a
different disk drive or device than the drive you usually keep the file on.
Nothing like a hard drive crash with your only copy of something like that on
it to really turn it into a really bad hair day.

"NickB" wrote:

I keep my work notes in a big Excel file, which I update and save to several
times every day. If I continue to save to the same file literally hundreds
of times, will the file become inefficient? Is the file rewritten each time
I save to it, or are the changes merely appended somehow?

Thanks!