Chrome and Safari keeps hanging after upgrading to macOS High Sierra
Frustrating to say the least.  try this: http://scaleup.us/2017/11/09/high-sierra-slow-chromefirefox-issues/

It appears to be an issue with the WindowServer running when running your display in scaled mode.  After setting the resolution for my displays to "Default for display" chrome and firefox issues disappeared.
Granted, the resolution is shit, waste of my 4k displays but, I'll take that over the freezing nonsense.