BAPI_0036_FIELDS 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 "GM : Single fields parameters for BudgetEntry Document" 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_BAPI_0036_FIELDS TYPE BAPI_0036_FIELDS.
The BAPI_0036_FIELDS table consists of various fields, each holding specific information or linking keys about GM : Single fields parameters for BudgetEntry Document data available in SAP. These include TESTRUN (Switch to Simulation Session for Write BAPIs), ACTIVITY (GM: authorization activity), GRANT_NBR (Grant), GETITEM (Get item data)... 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. .