Directly connecting AppleTV to Ethernet Cable

I have a single Ethernet line in my video room (unfortunately, my router and access to other ports is far away at the other end of the house). Today, I've been physically moving the line from my Internet TV to my new Apple TV and it handshakes and works great with each device.

What would be required to take this single Ethernet line and split it to 2 more devices? Any hints would be most appreciated.