The Microsoft.Office.Tools.Excel namespace includes the following classes:
Host item classes, including Workbook, Worksheet, and ChartSheet. For more information on host items, see Host Items and Host Controls Overview.
Host control classes, including Chart, ListObject, NamedRange, and XmlMappedRange. For more information on host controls, see Host Items and Host Controls Overview.
Classes that implement smart tag functionality in Excel, including Action and SmartTag.
Various helper classes, such as event argument and event handler classes for events in the Excel host items and host controls.