I've hiked up Table Mountain on a beautiful winter morning.
It took about 1,5 - 2 hours to get to the top via the Platteklip Gorge and it's totally worth it. The achievement doing it by foot is so much better than taking the gondola.
Do I write that because I couldn't use the gondola, as it was shut down for maintenaince work when I was there? Nope, I really think you should walk up there. It's not too long, but tough. But isn't it nice to say afterwards that you made the effort of "climbing" it?
I think I was lucky that the gondola was closed. That way there were only a few other people on the top. I guess I would have taken the gondola for the way down, but even the hike down was easier than I thought.
The hike up the Platteklip Gorge got many huge stones, which makes the walking quite easy.
Go for it! You will love it!
Are you up for a longer walk? Then take a route up on the 'back side' of the Table Mountain. I haven't done it, but I got it highly recommended by my guide, Margaret Curran. That hike will take about 6 - 8 hours. If you decide to do that one or have done it already, share your experience as a comment or as a single tip.