Safari Using too much CPU and Memory
While using Safari sometimes my fans ramp up due to overheating CPUs. Activty Monitor shows "Safari Networking" using 300% CPU and several GB of RAM.
I believe the problem is triggered by visiting some OWC (macsales.com) web pages such as:
https://eshop.macsales.com/search/?q=blu-ray&filter.catidpath=2224/2225
... either alone or when several other OWC web pages are opened in tabs. I have not noticed the problem with other websites (but it's possible I just didn't notice). Closing the OWC webpages usually allows the heavy CPU use to return to normal, but sometimes I have to quit Safari.
The problem does not occur in Safe Boot Mode.
If I delete the Cookie for OWC (macsales.com) the excess activity does not occur when I open the first OWC webpage - but that re-reinstalls the cookie, and opening a second OWC page cause the problem to return.
Can I assume the fault lies entirely with the OWC website, or is it possible there is something wrong with my system? I can post EtreCheck logs if necessary.
Safari 12.1.2 running under MacOS 10.12.6 on a 2011 iMac (iMac12,1)