LG V500 is the LG G Pad 8.3 and the LG V510 could just be another variant of the G Pad. An LTE version maybe. Or something else. Like an 8 inch Nexus tablet.
It is all speculation but with a yet to be announced Google event to unveil the Nexus products for the next one year about to happen soon, trust us paranoid gadget freaks to bring up every possible angle and twist to any news received.
Here is what has raised some alarm bells