In the skyrim creation kit, when you load a cell, it says a percentage and a number like 10mb/152mb

I am currently at 72mb but I expect it to dip into... Much higher numbers. I don't want to spoil the mod yet hehe.

Will this number going higher the. 152 cause any problems? And what is this number for anyways?

Thanks I appreciate it. I have googled a few hundred times but can't seem to find anything about it, so resorted to the forums.