This is a key rack shaped as a tap. In the back of the tap there is a hole to fit a strong magnet so that the tab kan be attached to any metal face such as a fridge door. In the spout of the tap is also space for a strong magnet so that you can attach keys to it. If your magnet is strong enough you should be able to attach keys to keys and create the effect of a stream of keys that is flowing from the tap.
I did design this Key-Tab in blender which is able to export the design as an .stl format so that it can be 3D printed. I added the .blend-file for those who want to try it. You can rescale it to your needs and you can also rescale the holes to accomodate your magnets before exporting it as an .stl