As a formalism, conventional decision tables are known to be well-suited for their structuring and organizing capacity of complex decision problems. Although they originate from computer science some three decades ago, recently decision tables have been found a most promising tool to model and support all kinds of (spatial) decision-making processes. In the present paper the theoretical basis and practical implications of such an approach are outlined and illustrated. In the theorical part decision tables are formally defined and their step-by-step construction discussed. In the practical part the issue of data collection and knowledge acquisition are illustrated by making reference to a real-world site selection problem of an industrial company.