FVBEL 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 "Assigns sub-leger docs to FI docs (with call transaction)" 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_FVBEL TYPE FVBEL.
The FVBEL table consists of various fields, each holding specific information or linking keys about Assigns sub-leger docs to FI docs (with call transaction) data available in SAP. These include GJAHR (Fiscal Year), BELNR (Accounting Document Number), RBELKPFD (Document Number of Document Header (Loan)), XBLNR (Reference Document Number)... 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. .