Roundtable discussions involve a group sitting in a circle to discuss an issue and share opinions. They work best with 6-8 people to encourage participation from all. The presenter should prepare main discussion points and questions to stimulate conversation. When facilitating, the presenter should stay on topic, avoid dominating, and move the discussion along smoothly. Different formats like going around the table or taking volunteer speakers can structure who contributes. The goal is for all attendees to have an open and equal chance to provide input to the topic.