The presence of an Ethernet port in the armrest of your Honda Accord 2005 (Thailand model) is unusual because Ethernet ports are not typically found in vehicles of that era. It's possible that the port you're referring to may have been added or modified after the vehicle was originally manufactured.
It's possible that it could be a modification made by a previous owner or an aftermarket addition for specific purposes such as audio or video connectivity, data logging, or other custom features.
If you're curious about the purpose or functionality of the Ethernet port in your Honda Accord, it would be best to consult the owner's manual or reach out to a Honda dealership or authorized service center for more information. They may be able to provide further insight or determine if any modifications have been made to the vehicle's original equipment.