Can I view cable on a seperate TV?

Hi. I hope my question is appropriate for this forum.

Here's my situation: I have cable TV in my living room and my computer is in the den right next to that room. When I set up my Comcast hi-speed internet connection I was given a splitter so that my modem would connect to my cable. I have a small 13" TV set in my den which does not have cable. I'm wondering if there's a way to use a similar splitter to connect to the antenna on the small TV so I can view the programs running on the TV in the living room. I'm not talking about a seperate cable line or box. I merely want to view on one TV what's showing on another.

Does this make sense? Is this feasible and legal?

Thanx

mccd