Assuming your TV is digital, it has a native resolution just like your monitor. If it's a 1080 HD display, the resolution is 1920x1080. If it's a 720 HD display, it's 1280x720. In your display settings you can set the resolution for each monitor independently.
If you set your resolution to anything less than the native resolution of the display, everything will look bigger on the screen. However this may also result in a display that is distorted and fuzzy, possibly to the point of being unusable. Try a lower resolution that is an exact fraction of the native resolution. If the display is 1920x1080, try 1280x720 setting - exactly 2/3rds of the native resolution.
It's easy to apply any new resolution to see what it looks like (click Apply, not OK). Windows will ask if you want to keep the new resolution. Good luck!