How to connect 3 computers to 1 cable in an existing local network?

Question

Computer networks

Good day. There is already a working local network on the TOTOLINK A3002RU gigabit router. From it, a cable (twisted pair) goes to each room. In one of the rooms there was only a home nas server, now it is planned to install a stationary computer and a TV there, and they also need to be connected via cable.
Question: how can I organize the cable connection of other devices from the cable that enters the room? As far as I read, you can use a switch (like TP-LINK TL-SG105), but I don’t understand if this can be done in an already prepared local network?

Answer 1

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