13. A method comprising: generating, using at least one processor, data used to display tabular data to a user, a first column of the tabular data being associated with a first entity type and non-heading rows in the tabular data representing entities of the first entity type in a knowledge document; permitting the user to select a second column of the tabular data and provide a second entity type as an object type to be associated with a labeled relationship represented by a heading of the second column; generating, using the at least one processor, an entity in the knowledge document of the second entity type that represents a value in a non-heading row in the tabular data; linking an entity of the first entity type that is associated with a non-heading row to the generated entity by the relationship; and storing an updated knowledge document in a memory.
13. A method comprising: generating, using at least one processor, data used to display tabular data to a user, a first column of the tabular data being associated with a first entity type and non-heading rows in the tabular data representing entities of the first entity type in a knowledge document; permitting the user to select a second column of the tabular data and provide a second entity type as an object type to be associated with a labeled relationship represented by a heading of the second column; generating, using the at least one processor, an entity in the knowledge document of the second entity type that represents a value in a non-heading row in the tabular data; linking an entity of the first entity type that is associated with a non-heading row to the generated entity by the relationship; and storing an updated knowledge document in a memory. 16. The method of claim 13 , further comprising: receiving a natural language computation for a subtype, the subtype being associated with the first entity type; parsing the natural language computation to determine criteria for the subtype; determining a plurality of entities of the first entity type meet the criteria; and displaying the plurality of entities in a tabular display for the subtype.