Stellenbosch offers a wide range of restaurants and bistros to suit all tastes and needs. Many of these are within walking distance from the congress venues. There are also many good grocery stores available for those who would prefer self-catering.
The main restaurant area is Church Street and surroundings, as well as Ryneveld Street. See http://www.stellenbosch.travel/dine.
The Neelsie Student Centre (on the central campus) offers cheaper fast food options.
The Eikestad Mall shopping centre is within walking distance from the congress venues.