.deb files are not binaries, they are archives and they can be unpacked to your device's memory
They can contain almost everything so be carefull when tou install them.
Only unpack .deb from safe sources
To use them,move them in USB mass storage memory and type in terminal(you need rootsh installed):
root
dpkg -i /home/user/MyDocs/x.deb
once it's installed, you can suppress the deb file


Edit: oops, I forgot that the last firmware can directly install them from file manager