This .NET class wraps the AcDbBlockTableRecordIterator ObjectARX class. 

That iterator is used to iterate through an BlockTableRecord.

Autodesk.AutoCAD.DatabaseServices.BlockTableRecordEnumerator

Public sealed Class BlockTableRecordEnumerator
Inherits DisposableWrapper
Inherits IEnumerator

public sealed class BlockTableRecordEnumerator : DisposableWrapper, IEnumerator;