In the 75gb column, all of those things add up to your total.
So it says you can do all that, aswell as looking at websites 24 hours a day, which i presume means actual loading pages not just having your computer switched on.
Until NTL do provide these tools, i recommend using a little program called NetMeter, easy to use, even for a noob like me
You can also set it to alert you when you are going over your limit.
http://readerror.gmxhome.de/