tlb) is a binary file that stores information about a COM or DCOM object's properties and methods in a form that is accessible to other applications at runtime. Using a type library, an application or browser can determine which interfaces an object supports, and invoke an object's interface methods.

How do I open a TLB file?

Applications that can be used to open and view the content of these TLB files include Microsoft Excel 2010, and non-Microsoft Windows users can also open and view these TLB files using Microsoft Excel 2011 for Mac systems. Some users reported the stdole3.

What is a TLB file Visual Studio?

A TLB file is a small file to help accessing a DLL. This is true for COM or DCOM object. You will use TLB files if for example you make a DLL with Visual Studio 2010 (C# or VB) and want to make if COM visible.