That's nothing but a jack plate for running composite video over coax...
Look, here are your choices:
Modulate into RF - composite grade SD video + mono or stereo audio, multiple channels on one coax
Composite video - composite grade SD video only, one source only on one coax (IE a VCR output ONLY)
Digital audio - one coax
Analog audio - two coax's for 2ch
S-Video - two coax's for one source only
Component video - Three Coax's for one source only
So, in summary if you want to watch a component video source in HD w/ 2 ch audio you need FIVE coax's to that one TV. If you want to distribute multiple sources to multiple TVs you'll need a Matrix Switcher and 5 coax's from the switcher to EACH TV.
There is no consumer means to encode/decode multiple sources of HD video onto 'channels' that can be sent on a single coax. Cable companies do it with very expensive equipment. You cannot.
There are also no coax baluns equivalent to the cat5 baluns because there simply aren't enough conductors in a single coax cable (two vs eight in a cat5).