1. A computer system for modeling tabular data with mixed column and pivot table layout the computer system comprising: one or more computer processors; one or more computer-readable hardware storage media; program instructions stored on the computer-readable hardware storage media for execution by at least one of the one or more processors, the program instructions comprising: program instructions to receive tabular data containing a set of columns and rows, from a data source, wherein columns in the set of columns contain a category label and metric data; program instructions to determine, for one or more columns in the set of columns, a corresponding metric type; program instructions to identify grouped and ungrouped columns in the set of columns, wherein grouped columns comprise one or more pivot type columns, wherein a pivot type column corresponds to a column sharing a predetermined metric type with an adjacent column, and wherein ungrouped columns comprise one or more columnar format columns, wherein a columnar format column corresponds to a column having unique metric types compared to adjacent columns; program instructions to generate a table comprising a first sub-table and a second sub-table, wherein the first sub-table further comprises the tabular data of the ungrouped columns and the second sub-table further comprises comprising the tabular data of the grouped columns, and program instructions to identify n columns, wherein n is a count of columns in a largest group of columns in the identified group of columns; program instructions to identify m rows, wherein m is a count of rows of metric data in a largest column within the identified ungrouped columns; and program instructions to generate the first sub-table comprising (n×m)+1 rows, the (n×m)+1 rows, wherein the first sub-table is populated with the category labels and the metric data of the ungrouped columns, and wherein the metric data of the ungrouped columns is repeated n times.
2. The system in accordance with claim 1 , wherein program instructions to generate the second sub-table further comprises: program instructions to determine first and second semantic category labels for one or more columns in the grouped columns based on corresponding category labels and metric data; and program instructions to generate the second sub-table comprising two columns and (n×m)+1 rows, wherein a category label of the first column is populated with the first semantic category label, a category label of the second column is populated with the second semantic category label, rows of the first column are populated with category labels of the grouped columns repeated m times, and rows of the second column are populated with metric data from the grouped columns.