Ryan cokes are the most space consuming thing, they are pretty much worthless so sell them when you don't plan to use them. I stored like 3,000 on a mule and now I just sell them all the time.
It's also good to note that if you don't use your healing items that they also take up a lot of space. My Asura is pretty self-sufficient so he has a bunch of items on him, every 100 usable items is 2kg of space. I suggest storing them on a mule or something until you need them.
Plate armor = space consumer. This is why I farm using my grappler who only uses 2/5ths of her inventory space on her equipment.
"There once was a boy who dreamed of being a hero. Who believed sincerely in the battle to banish darkness from a world of light... but light and darkness are equal... and where one exists so too must the other... and when the boy finally realized this he had taken the first step toward being a true hero."