Looks like you got only 2 1/2 hours of actual use (screen on). Most of the drain was the wifi and mobile staying on while the tablet was supposedly asleep. I don't have the 3g but in settings, wifi, menu, advanced, you can set the wifi to turn off when asleep. As far as the awake spikes while the screen was off, turn off auto sync in currents, locale, weather etc. On google play is a program called 'wakelock detector' to help track those down. Look at the partial wakelocks (screen off activity).