That's a decent total for idling, which is what most PCs do 99% of the time. Surfing the web is effectively idling to a modern CPU.
When you have (in my example) 6 cores that can run up to 5.3GHz, they do quite a lot of work in a very short period of time and then drop back to sipping next to nothing.
The CPU can be one of the biggest power draws in the system if you load it up, but most of the time powering things like disk and RAM actually take more power. Same goes for the graphics card, if you have one. It only sucks 200W during gaming and next to nothing the rest of the time.
145W TDP just means that it could possibly, at max tilt, draw that much. But really Intel separates them into classes (95, 125, 145, etc.) so it's unlikely that it would even draw that much except for very brief periods. Intel sets things up so that the CPU can draw over the TDP, but for a couple of seconds at most. Then it drops back down below it to stop from frying.