1. A method comprising: generating an underlying data model associated with a visual data model of a spreadsheet containing a decision table, wherein the visual data model comprises a graphical coordinate system corresponding to display of the spreadsheet comprising the decision table; populating, via a processing device, the underlying data model related to information contained in the visual data model and the decision table, wherein the underlying data model comprises a logical coordinate system; generating a first index to map cells in the visual data model to cells in the underlying data model consistent with the decision table, wherein the first index comprises a first plurality of cells, each cell of the first plurality of cells comprising: a cell value, a coordinate in the logical coordinate system, and a coordinate in the graphical coordinate system; generating a second index to map cells in the underlying data model to cells in the visual data model consistent with the decision table, wherein the second index comprise a second plurality of cells, each cell of the second plurality of cells comprising: a cell value, a coordinate in the logical coordinate system, and a coordinate in the graphical coordinate system; generating a cell merging table associated with the first index, wherein the cell merging table is indicative of a number of cells each having a same value that are merged into a single cell in the decision table, wherein the merged single cell having the same value, and wherein a location corresponding to the merged single cell is populated by a number of merged cells value reflecting the number of cells each having the same value merged at the location.