Unwrap the tape and remove the choc blocks (remember to turn electric off or isolate the circuit) bring the cable out higher if it suits better. Fit a 13A socket onto the existing cable but write/label print 6A max onto the socket where it can’t be seen when fair lights plugged in for aesthetic reasons, as suspect it’s coming off the lighting circuit. Then plug your fairy lights into it. You could also use a drywall box to flush mount the socket.
Is this suitable or were you thinking of something else?