A DWT file is an AutoCAD drawing template file that is used as a starter for creating drawings that can be saved as DWG files. Such template files provide initial settings such as unit types, the precision required, title blocks, layer names, line types, and other similar information for lateral conversion to proper drawing files. Both AutoCAD and CoreCAD can be used to read the template files and utilize them further.
XLAM files are used to extend the modules provided by Excel. They can be added to Excel 2007 or later, or to earlier versions of Excel with Open XML component support. File used by Microsoft Excel, a program that allows users to create and edit spreadsheets; contains a macro-enabled add-in, which provides extra functionality and tools that may execute macros.
You can also convert DWT into many other file formats. Please see the complete list below.