This is the original cat 5 termination, its correct name is the M-66 block. Used for phone and data (10 base T). It was used for years after data gained popularity and higher speeds required a better terminal. The good news is the cat5E cable is still very usable for data. It may not get you gigabit speed but more than sufficient for general household PC use.
When running a new connection cat 5E/6 cable is far better than coaxial cable. Cost wise, performance wise and logistically it makes sense to go with the Ethernet cable like a modest cat5E cable