IGM_LISTHEADER_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 "Object and Action Information in ALV-GRID List Headers" 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_IGM_LISTHEADER_DATA TYPE IGM_LISTHEADER_DATA.
The IGM_LISTHEADER_DATA table consists of various fields, each holding specific information or linking keys about Object and Action Information in ALV-GRID List Headers data available in SAP. These include DATA_INFO (30 Characters), COLUMN (GM LIst Headers: Number of Columns), COLOUR (GM ALV GRID Lists: Color Attribute Values for Screen Docum.)... 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. .