Apps I didn't install with Android Logo. Do I need them?

Trying to clear up some space on my nexus 10 and find a bunch of apps in setting/apps that I am not convinced are genuine. They have important sounding names and an android logo next to them but I am not sure if my tablet will go Hal on me if I delete.
Titles like:
"android work assistant"
"captiveportallogin"
"device provisioner" etc
and a whole host of others clogging up my apps list. Can I delete them or are they official bits and pieces I need installed by google?
Thanks