Yep. It will depend on the service, but role plays are often where you are asked to play out either a common situation within a service or a tricky situation. This is to check your engagement and rapport skills, as well as how you handle being under presssure and you are not going to be expected to deliver an entire intervention or anything. Also you shouldn't be put into a situation beyond your capabilities - they are not going to ask you roleplay the job of an 8b or anything.
Data tasks are just that and the tasks we use most often in recruitment. You may be given a set of raw data and be expected to work with it to produce routine stuff that would come under an audit. You may be required to categorise it, or just analyse it. Consider the basic audit questions that may be asked, such as pre and post intervention comparisons. In 20 mins you aren't going to be asked anything really taxing beyond what most psychology graduates will have covered in their research methods.