Hiking Table Mountain almost always involves some degree of exposure to heights – even A-grade (lowest level of difficulty) routes like Skeleton Gorge and Kasteelspoort. For those unfamiliar with the term, exposure to heights basically means nearness or proximity to sheer or steep drop-offs. There are shades of grey: the exposure in Skeleton Gorge is mild compared to that on the Grotto-Cairn Traverse, which could be classified as severe. Most people can deal with a bit of exposure while hiking Table Mountain, especially when accompanied by a Table Mountain guide.
Why would you chose a route with exposure to heights when deciding what route to do? To add spice / adventure to a route. Exposure to heights does not make a route more technically difficult, in theory; in practice, a route can feel harder because of the exposure. Most people tense up when in close proximity to a sheer drop, and the simple act of walking can become awkward and even challenging. If you have at least a fairly good head for heights and you’re adventurous and / or up for a challenge, then picking a route that involves exposure to heights is highly recommended.
It’s important to do exposed routes in the company of an experienced hiker who knows the route; or make use of a Table Mountain guide. People are sometimes surprised how they react to heights, and it’s often with more trembling and nerves than they expected; so good to have someone around to guide you along the scary bits. Also, lose rock poses a huge danger: you need a practiced I to discern between what you can pull on and what not.
Picking a route that involves exposure to heights is a sure-fire way to crank up the adventure level of a route. Most Table Mountain hiking routes involves exposure in varying degrees, so you have the option to choose the severity.