I would suggest that the Time Machine back-ups be done with an external hard drive. After the back-up is done to the external hard drive, turn off Time Machine. After you power up your lap top again, the back-ups under the disk utility storage window should show zero KB.
What I have found that the "other" files were, for me anyways, was from my iTunes. I moved my iTunes to an external hard drive because it was over 300 GB and my hard drive is only 500 GB. From what I can gather is this. When you de-select something in iTunes for your iPhone, iPod, or iPad, what was deselected gets "deleted" from the device and goes into the "other" catagory. I am guessing as you are not actually deleting it from iTunes, just a device. Deleting a copy. I only happened to notice this because I have a 3rd party wiping program called BCWipe. And after I had un-selected a couple movies on my iPad and synced, I did a wipe of my trash. In my wipe program window I happened to see a lot of iTunes files with the .trashes extension. So after it was completed I went back to the storage window and you can see below that it cleared it all up. The trash icon in the dock was showing to be empty, even before I wiped the trash.
I have seen a lot of posts state that there are Pages/Numbers/PDF files that are also stored under the "other" section but I don't think that is true because I have nothing in the stored as other (see below) and just over 27 GB in the Apps. So I believe that these documents are kept within their appropriate application.
I just want to add that this was using MacBook Pro with Mavericks.