Any chance of putting a measuring tape next to that for accurate scale? Looks short for bayonets of the time. Same pattern as the SMLE bayonet and that would fit with the Africa reference as some of the LRDG didn't adopt the Lee Enfield no4 (and its spiked bayonet) and stuck with the SMLE but it looks a bit too short for that
not a SMLE bayonette (actually have one from the boer war era) the SMLE bayonettes (and all british bayonettes right up through WW2) the guard tang, pommel and blade are all one peice with the handle simple scales riveted on and do not have fullers (aka blood groves) at least pre WW2 ones (can't remember if the service bayonette from WW2 had a fuller but I know the one made for home guard units didn't) (though in the one I got it's hard to tell if the guard and blade are one peice or two as it spent deccades buried under the ground)
the stamp on the tang looks like a german or possibly swiss stamp
as there is no sign of rivits on the handle then I would say it is most likely a knife not a bayonet, (as most bayonets of the period used a simalar design for the handle, (namely a pommel that was part of the tang, with a pin on one side to connect to the spring mechanism, with the tang retaining the full width of the blade)
though with all that said it does bare some resemblance to the german made bayonets issued to the ottoman turks during WW1. but after extensive search can't find any matches for service issue bayonets in any military, so it's most likely a knife, which could be harder to find out as it could be a service issue or a civilian knife