I am only one day into the creation kit so I don't know any more then you but did you under the file tab select data then double click skyrim esm. The box should should now have an "x" in it, then click on "ok" It may take a while to load so wait for it. You will also get a warning box just click "yes to all" and let it finish loading the cell view box should be full now. I suggest you go to Wiki and read the tutorials. I dont know how to add links here so just do a search for the "creation kit" and you should be able to find it from there. Be careful you could really mess up your game if you do something wrong.
I just checked this, it is also posible to drag the box closed to the bar so that only the bar shows this may also be the issue.