1. A method comprising: receiving a file comprising a plurality of entries, each entry comprising one or more data items separated by one or more delimiters, each data item having an ordinal position within the entry; causing display of a table in a graphical user interface (GUI), the table having one or more rows each having one or more columns, wherein each of the data items of a particular entry of the file appears in a respective column of the same row of the table, each respective column corresponding to the ordinal position of its respective data item within the entry; receiving user input designating, for each respective column, an element name and a type of entity definition component to which the respective column pertains; and creating or modifying an entity definition stored in computer memory, including storing for each of the data items of the particular entry of the file a value of an element of the entity definition, wherein: the element of the entity definition has the element name designated for the respective column in which the data item appeared, and the element of the entity definition is associated with an entity definition component having the type designated for the respective column in which the data item appeared; wherein the entity definition represents an entity having corresponding machine data; and wherein the method is performed by a computer system comprising one or more processing devices coupled to the computer memory.