Help freeing up space please


Hi. I'm running a cheap chinese tablet (Kocaso M776) with ver 4.1.2 on it. It's got 512mb RAM & 4GB of "internal memory" & a slot with a 32GB micro SD card. I keep getting a message for running out of storage space so I want to delete as much bloatware as I can.

I've rooted the tablet using Kingo & installed System App Remover from Playstore.

When I look at the apps, it's telling me that most are either "Key Module" or are marked as "Should Keep"

I need to know what it is safe to remove. Surely things like Angry Birds, Fruit Ninja or the Amazon Kingle app can't be Key Modules??

All I really want at the moment is basic internet & e-mail access & a SAT-Nav app in addition to the camera & phone stuff. Just one browser, No live wallpapers, Office Suite or Skype or Twitter. Then I can decide what I want to put on it.
Thanks to anyone who can help.