FMKF_KFS 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 "Key Figure Structure" 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_FMKF_KFS TYPE FMKF_KFS.
The FMKF_KFS table consists of various fields, each holding specific information or linking keys about Key Figure Structure data available in SAP. These include KEYFIG (ID of the Key Figure)... 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. .