Yes, it does have an Ethernet port - this is part of the FreesatHD specification.
However, unlike the G15 and V10 models which are immediately 'above' the G10 in the Panasonic range, it doesn't currently serve any function - as the G10 (UK variant, at least) does not have the VieraCast function.
As has already been mentioned it is likely that it will be made available when the BBC iPlayer is formally launched on Freesat.