Your LG PC Monitor is whats called a 6-bit TN LCD Panel. It can not display a full range of colors.
You can watch TV, just fine on it but HDTV's Panasonic, Sony etc. use 8-bit LCD panels or 10-bit IPS Panels in Panasonics case. And Some Sony' are 10-bit also
You should be perfectly happy watching TV on it. I am when I watch TV on my Samsung XL2370.
As long as you have some type of Hardware TV Tuner, and Digital Cable, or Satellite TV, or Direct TV, some digital signal.
But SD cable analog cable standard def channels will look especially horrible. But if you connect it to a SD CRT Tube TV they would look crystal clear. Analog TV's will always be better at displaying Analog signals.
But if you are digital and have digital cable it should be ok. Not great but ok. It also says it has an MPEG 4 TV Tuner, I have no idea what that is. HDTV's have QAM Tuners for picking up Cable, and ATSC Tuners for Digital Signals and Digital Cable, and NTSC Tuners for Analog Signals.