BP1012_KEY 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 "Business Partner: Ratings" 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_BP1012_KEY TYPE BP1012_KEY.
The BP1012_KEY table consists of various fields, each holding specific information or linking keys about Business Partner: Ratings data available in SAP. These include DIFTVAL (Differentiation Criterion), DATE_TO (Valid-to Date for Rating), GRADE_METHOD (Rating Procedure)... 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. .