If it is showing usage, it is probably doing something, although it may not be from the internet but your local LAN. Transferring a file from one system to another would probably show up.
Sudoku has used 17 MBs in the "Last 30 Days" so I have to assume that is either some update or more likely the streaming ads. I am also not sure yet what the time frame means. It would be nice if you could reset to match some specific period, such as you internet bill.
You can see Windows Media Player seems to spend some time with its service running checking other systems. But it does give you a feel for what might be happening on your network. It would be most useful for folks with metered network connections. I will have to look and see if...