CMS_STR_ENTITYID 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 "List of Entity IDs(AssetID or Agreement ID or Obligation ID)" 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_CMS_STR_ENTITYID TYPE CMS_STR_ENTITYID.
The CMS_STR_ENTITYID table consists of various fields, each holding specific information or linking keys about List of Entity IDs(AssetID or Agreement ID or Obligation ID) data available in SAP. These include TYPE (Entity Type), ASSETID (Asset ID), CAGMTID (Collateral Agreement ID), RBLID (Receivable Identification Number)... 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. .