It doesn’t have 3G/4G slot.

There are several use cases:

  1. Wireless to Ethernet. Use this when you use public wifi

  2. Repeater, wireless to wireless

  3. Mesh node, you can install opensource mesh protocols e.g. Batman-adv and use it as mesh nodes.

Of course you can share PC’s connection to wireless, but you may need to have some setup in your pc.