i have the same thing, its really annoying, it happens when i swipe to go back, it just sort of freezes and i have to restart safari just to get it working
Was having this problem in Safari and Chrome. Temporary solution for me was to disable swipe left/right gestures in system preferences and creating said gestures in BetterTouchTools for all of my browsers. Hope this issue gets fixed soon.
In Finder, select Go > Go to Folder from the menu bar. Copy and paste the following path into the input box and then press Return:
~/Library/Safari
Remove both the Extensions and Databases folders. This will require you to reinstall all extensions but will also resolve the problem.
It seems that 10.9 may not properly migrate some data during the upgrade process.