I can cover kingdoms but not be touched or seen; Rulers judge me yet lovers endure me. What am I?

My first three: of earth, though I dwell not in soil, My last three: an effort, through my study you toil. Between them, the self that one catches in name. Together, I order the world into frame.

In the past I was ten to the power of four, but now I can be less or I can be more. Some people would say that as a noun I'm improper, but noun before adjective, in that form I first prospered.

Turn me on my side and I am everything. Cut me in half and I am nothing.

I hold plates and start conversations. I list elements and order facts. I arrange rows for numbers and columns for decisions. Set me for dinner or set me aside in debate. What am I?