Digital tabletops are gaining increasing relevancy within commercial and educational sectors, as they have the unique quality of fostering collaborative learning by engaging users in the activity. For multi-tabletop learning situation, there are two levels of collaboration, collaboration at tabletops and collaboration through tabletops. Our research interest focuses on how group activities on tabletops could potentially encourage different levels of collaboration to favor learning. Although the design process of serious game is costly and time consuming, it is still increased with tabletop applications. The main goal of this research is to design an authoring tool for serious game on multi-tabletop, which will allow non-experts to create mini-games for learning in an efficient and structured way.