I tried the minimal image, and that seems the be better.
debian@BeagleBone:~$ df -h
Filesystem Size Used Avail Use% Mounted on
udev 215M 0 215M 0% /dev
tmpfs 49M 1.3M 48M 3% /run
/dev/mmcblk1p1 3.5G 856M 2.5G 26% /
tmpfs 242M 0 242M 0% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 49M 0 49M 0% /run/user/1000
I’ve installed samba which takes up 100MB, but otherwise it seems to be fitting…