Changing two gang wall socket to a three gang socket(MK triple)

I want to change a two gang wall socket to a three gang socket , its an MK triple fused socket and i understand the 13 amps is between the three sockets. What will be plugged into the new socket is a surge protected trailing extension lead with a soundbar and a freesat box and amazon echo, the next thing is a single socket extension which will power a television and the third will be a ethernet socket . Would the socket cope with this, the two gang socket has two sets of cable but there is a socket the other side of the wall feeding that socket but again has two cables i also know i will have to replace the back box all this is no problems my main question is of the new socket will cope or go for another two gang next to the the other if indeed the socket is not a spur thank you everybody. Thanks for all the help so far, would like to know if the worst case scenario the double socket already there is a spur is it still ok to swap to a triple gang socket . regards bill