I would only install the updates and fixes that you actually need..ie if you have that specific problem...............i've got so much hard disk space it doesnt make a dent in my storage space..buts thats no excuse!
what hotfix's did you download that are 312mb? That must be an error in reporting how much disk space they are taking up...do you really remember downloading 312mb times 7 = 2184mb from windows update?!
That "Size" is the size of the folder they're installed to, NOT the size of the files associated with that program, so whatever folder these hotfixes are installed to, the same filesize should show up under each one.
Odd thing, though...I dont have a filesize listed for a single Hotfix in my Add/Remove Programs list...maybe you should try running Disk Cleanup...see if that changes anything.