I recently bought Lenovo IdeaTab Lynx K3011 tablet that came with Windows 8 Pro preinstalled on it. Although it didn't have too much crapware, I'd prefer to have a fresh copy of Windows without Norton deep-seated in it, etc. Is there any way I can download Windows 8 from Microsoft and reuse whatever is needed for registration?

No.  You would have to reinstall Windows 8 using the Lenovo recommended reinstallation procedure.

get a clean MSDN/Technet ISO and install Windows again. The Setup will use your OEM Key which is embedded to the UEFI.

@Andre, thanks, man. Sounds like a really good idea. Although I'm trying to find the Windows 8 ISO and all I get from MS is 8.1 demo. Any idea where to get it?