Each row and column on the output FlexPivot table is defined by a unique PivotKey. The values in the table cells represent an aggregation of the value field for all items that match the row and column keys.
For example, if a column key is set to 'Country:UK;Customer:Joe' and the row key is set to 'Category:Desserts;Product:Pie', then the corresponding cell contains the aggregate for all items with the following properties: 'Country:UK;Customer:Joe;Category:Desserts;Product:Pie'.