Table annotation is the task of annotating a table with terms/concepts from knowledge graph or database schema. Table annotation is typically broken down into the following five subtasks: Cell Entity Annotation (CEA) Column Type Annotation (CTA) Column Property Annotation (CPA) Table Type Detection Row Annotation The SemTab challenge is closely related to the Table Annotation problem. It is a yearly challenge which focuses on the first three tasks of table annotation and its purpose is to benchmark different table annotation systems.