Yes,
Especially if you mostly went with default installs.

You can go into Application Manager and look at installed software and it'll show you what each application is taking.

Then you can choose to uninstall something from there.

One thing that nailed me when I was first using my tablet was Maemo mapper.
I put my maps on my memory card. But then I redownloaded map repositories and wasn't paying attention and when I downloaded new maps, they went to the regular filesystem. That didn't take too long to fill up my 770. :-)

desiv

WARNING, serious GEEK-NERD hint ahead!!!
OK, if you want, you can go into a terminal and type this: (It's tricky!!!)

du -h | grep [0-9][M,G]

OK, after the "-h" is a space and then a "pipe", it's available with the onscreen keyboard under "Symbols".
Basically, it will look in all the directories from your current path (should be /home/user) down and give you file sizes for each directory, but since that would be WAY too much info, we pipe it into grep.
"grep" is pretty easy to understand. It's basically the GOD of command line!!! All HAIL GREP!!! :-)

OK, what that does is show you just the lines that have a number [0-9] followed by either the M or the G [M,G].
So, you'll only see entries like:
1.0M ./.canola/covers
1.5M ./.canola
Which means my canola directory and all its subdirectories is 1.5M in size, and the directory covers inside .canola is 1M of that.

Usually, I'll do a du -h --max-depth=1 on a Linux box, but the 770 dh command doesn't understand the max-depth option. (Don't list subdirectories more than the max-depth)
(sorry, I was feeling extra nerdy and couldn't help myself. :-)