FMKU_S_MIGRATE_SOURCE 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 "Structure of source fields of FBS to migrate to BCS" 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_FMKU_S_MIGRATE_SOURCE TYPE FMKU_S_MIGRATE_SOURCE.
The FMKU_S_MIGRATE_SOURCE table consists of various fields, each holding specific information or linking keys about Structure of source fields of FBS to migrate to BCS data available in SAP. These include FISCYEAR (Fiscal Year), WRTTP (Value Type), SUBVO (Budget Subtype), VORGA (Budget Type Budgeting/Planning)... 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. .