What more can I tell you ? The entries you can uncheck are applications not needed at Startup. They only slowdown your Startup time. You can access these applications manually anytime.
If you want an idea of what the applications are, and if they are needed at Startup, just enter them one by one
here.
And, as I've already written, if you want these applications back in your Startup list, you only have to recheck them again quite easily. No harm done.