GRAC_S_API_REQSYS 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 "System data" 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_GRAC_S_API_REQSYS TYPE GRAC_S_API_REQSYS.
The GRAC_S_API_REQSYS table consists of various fields, each holding specific information or linking keys about System data data available in SAP. These include SYSTEMS (Connector Id), SUBSYSTEM (Connector Id), USER_GROUP (User group), LIC_TYPE (ID for the User Types of the SAP System)... 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. .