If you plug and unplug the main ethernet cable (RJ45 / CAT5) often, the connector can get damaged. If you are using an internet connection with frequent downtimes, a problem with connectors can make troubleshooting more difficult.
In such cases it is better to use a splitter and 1 or 2 RJ45 cables , so that the damage due to wear and tear is minimized.
RJ45 Cables which are 1.5 m long cost less than $1 (Rs 40)
A splitter costs about $ 2.5 (Rs 100)
It also makes it easier to connect to multiple computers or a desktop / notebook combination .