The Pipe Track is one of Cape Town's easiest hikes along the side of Table Mountain. It starts at a convenient spot with plenty of parking, just above the city centre, and follows a leisurely path along the back of the mountain, showing off the splendour of Camps Bay, the Atlantic Ocean, and the Twelve Apostles mountain range.
The path is well-frequented, especially on warm and windless Saturday mornings. I think the best time to walk the route is in the early morning, just as the sun rises over the Boland mountains. Around this time of the year in particular you'll find that the air is crisp and clear, and that the wind hasn't yet had time to awaken.
There are generally many people walking the route in the morning if the weather's good. However, if you decide to take the walk when there aren't so many folk about, then perhaps you should consider walking in a group of at least four people. It's a very isolated part of the mountainside and although unlikely, it's possible that muggers could wait there to help you carry your cameras, wallets and phones. ;-)
Take a look at this map of the Pipe Track. This route is about 3.5 kilometres long (one way) and should take you about an hour to complete. So, to be safe, set aside about three hours for this trip. The extra hour will come in handy for taking in the sublime views!