I realised that my Word2016 (under Windows 10) saves a lot of *.log files under

C:\Users\<username>\AppData\Local\Temp\Diagnostics \Winword\

How can I instruct Word to delete these (*.log) files AUTOMATICALLY on exit?

I think you'll find that those files get deleted automatically after a week or so. There's usually nothing of significance in them anyway.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]