You could terminate the conductors in connector strip and fit a blank plate
If you wanted to loose it competely you'd have to disconnect the other end totally, and I'd not generally recommend this course of action.. if anyone ever needed to re-instate it then they'd have to dig to find the point, and then find out where the other end is, etc
Personally if it were me, I'd either leave it exactly how it is, or convert it to a socket outlet
Incidently, how have you powered the spark generator on the gas cooker?
A little concerned that all your breakers seem to be C-type, (are they all C type? or just the few you've listed?) normal thing in a house is B types for most stuff and the occasional C as and where required, having a domestic board full of C types begs the question of why!, who fitted the board? have you got a certificate for it?