PCA_BLOCK_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 "Key Structure Block Card Master" 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_PCA_BLOCK_KEY TYPE PCA_BLOCK_KEY.
The PCA_BLOCK_KEY table consists of various fields, each holding specific information or linking keys about Key Structure Block Card Master data available in SAP. These include CARD_GUID (GUID of a Payment Card)... 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. .