Hai TafeH
The D-Link is a mobile router, meaning you connect to the router with wifi/wifi and it translates to mobile 4G LTE. This one does not have an RJ45 port. If you want to connect a surveillance camera that "only" has RJ45, then you need a router with RJ45 (and I assume that you then transmit the data via the 4G-LTE network (wherever)?).
So, something like this for example:
Netgear Hotspot Nighthawk M1
And a mobile subscription to go with it... And before that, you have to check whether you have mobile 4G/LTE reception at all where the router is to be placed.
The 150Mbits apply to the LTE/4G (i.e. to the internet), the 300Mbit apply to the WLAN (within the WLAN LAN).
Hope that helps. LG