IBEXTINST_DATA 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 "IB: Table IBEXTINST Data Body" 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_IBEXTINST_DATA TYPE IBEXTINST_DATA.
The IBEXTINST_DATA table consists of various fields, each holding specific information or linking keys about IB: Table IBEXTINST Data Body data available in SAP. These include EXT_INST_ID (Globally Unique Identifier), LOGSYS (Logical 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. .