I had a website which was using massive amounts of memory on my MacBook but I was unable to take a screenshot of the total memory usage from Activity Monitor to file an issue with the website. Is there any way I can see the log of the Activity Monitor from a specific time?
If you want to redo the issue and collect data:
Download Xcode from https://developer.apple.com
Use Instruments.app with "Activity Monitor" instrument.
Choose all processes. Hit the red button to start recording.