I have a Surface Pro that I use when I am travelling. When you are travelling (I do little of it nowadays) you will find yourself in locations (strangely) that still has an Ethernet port available but no Wi-Fi. In some hotels Wired (Ethernet) Internet may be free, but Wi-Fi chargeable. So it’s good always to be able to connect one of your device to wired ethernet. Surface Pro, just like MacBook Air or iPad doesn’t have an Ethernet Port. To connect you will need a USB to Ethernet Adapter. I was having one inexpensive one when I was using MacBook Air few years back, that I seemed to have misplaced.
I went to my local electronics shop and bought the below device. It was a Chinese made device called “Live Tech USB 2.0 LAN Adapter” that costed Rs.390 (USD 6) . Plugging it in Surface Pro, Windows 8.1 immediately recognised the device and installed the necessary drivers. I was up and running in few minutes. Speed was good for normal usage that I tested on.