Update:
I received an email from Parallels support...
"I understand that you are facing issues with Google chrome tabs being hanged while switching between each other in Windows 8 Virtual Machine.
Martin, please follow the steps mentioned below:
1. Change the 3D acceleration to DirectX 9 and DirectX 10 and check with both the settings.
Launch Parallels Desktop => Click on "Virtual Machine" option on top Mac menu bar => select "Configure"
In Configuration, click on "Hardware" => Video => 3D acceleration -> DirectX 9 or DirectX 10
2. Assign 1 GB Video RAM.
3. Update the Flash and Java for Chrome.
4. Uninstall Google Chrome and re install it and check with the issue.
Please update us on the status of the issue.
If the issue persist, please feel free to contact us back for further assistance."
So I tried this and it did nothing, same issue. After researching this some more I tried several options via command line switches and found one that wipes this issue away. Try adding the command line switch "--disable-accelerated-compositing" (note double dash at the beginning). Although this works, it does hinder the rendering somewhat of chrome, not sure to what extent as I am still testing. Just wanted to update everyone of my findings. I let support know and I'm waiting to hear back.