Platteklip gorge is a great start to many hikes on Table Mountain, and it is only about 20 minute walk up this well known trail, then you will take a left turn at a sign pointing towards Devils Peak. I much rather prefer hiking this slight detour than having to slog up the endless zig zag at the “official” start of the Devils Peak hike on Tafelberg Road.
We also can never fully agree which hike is more difficult ‚ Platteklip Gorge or Devils Peak. Devils Peak via Platteklip Gorge is most certainly slightly longer, but in my opinion not as taxing on the body and you have much more scenic views to enjoy. If you do not enjoy the crowds that you always encounter on Platteklip, then this hike might be more for you, but I can almost say with certainty that here you also will not have the mountain for yourself.
On your way back down from the summit you also have a whole bunch of detours to choose from that will still allow you to walk a circular route. Purchase a good map of Table Mountain and you will be surprised at the number of options that are available to you.