BAPI_TE_FMBL 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 "BAPI extension table for entry document line (BUS0050)" 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_TE_FMBL TYPE BAPI_TE_FMBL.
The BAPI_TE_FMBL table consists of various fields, each holding specific information or linking keys about BAPI extension table for entry document line (BUS0050) data available in SAP. These include FM_AREA (Financial Management Area), DOC_YEAR (Document Year), DOCUMENT (Budget entry document number), ITEM_NUM (Budget entry document line)... 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. .