Opening gnome-control-center Wacom settings gives "(gnome-control-center:1900): libwacom-WARNING **: Tablet 'usb:056a:0014' has no buttons defined, do something!" message. No buttons to configure there. I can manually configure FN1 and FN2 buttons with 'xsetwacom set 'Wacom Bamboo pad' button [...]'. FN1 is button 1, FN2 is button 3. Arrow buttons configuration has no effect, pressing them scrolls page in web browser up/down.
xsetwacom worked some time ago, unfortunately can't tell when stopped, because I didn't used the tablet for a long time. Stylus works fine.
lsusb: Bus 001 Device 004: ID 056a:0065 Wacom Co., Ltd Bamboo