KPU3_CTRL is a standard SAP Structure so does not store data like a database table does. It can be used to define the fields of other actual tables or to process "Control Structure for Plan->Plan, Actual->Plan" Information within sap ABAP programs. This is done by declaring abap internal tables, work areas or database tables based on this Structure. These can then be used to store and process the required data appropriately. i.e. DATA: wa_KPU3_CTRL TYPE KPU3_CTRL.
The KPU3_CTRL table consists of various fields, each holding specific information or linking keys about Control Structure for Plan->Plan, Actual->Plan data available in SAP. These include FLG_TEST (Indicator: test run), FLG_CLTEXT (Copy long texts), FLG_UPDATE (Reset/overwrite data (X), or do not change ( )), FLG_CKALK (Copy costings?)... See below for full list along with technical details, documentation, text table, check tables, foreign key relationships, conversion routines, relevant tcodes and example ABAP select code etc. .