rsync or scp are the usual ways i think. you have to install some other stuff if your pc is windows probably to get those to run, not sure.

maybe you could run a web server too and have a page like directory listing with all the files and wget mirror one level deep to the device

you could also maybe install a syncml server on pc and use a syncml file source to sync files

f you install an aftermarket kernel or add kernel mods for cifs support, i think you could use wizard mounter for cifs shares and just use copy paste

there are probably more ways too