TypeLib Table

The Typlib table works the same way that the Self-Reg table does, it performs a Registration call against a file (the key file for a particular component).

Quoted from Microsoft:

Installation package authors are strongly advised against using the TypeLib table. Instead, they should register type libraries by using the Registry table. Reasons for avoiding self registration include:

If an installation using the TypeLib table fails and must be rolled back, the rollback may not restore the computer to the same state that existed prior to the rollback. Type libraries registered prior to rollback may not be registered after rollback.

http://msdn2.microsoft.com/en-us/library/aa372092.aspx

This may also be viewed under Windows Installer best practice guidelines:

Do not use the SelfReg and TypeLib tables!

Installation package authors are strongly advised against using self-registration and the SelfReg table. Instead they should register modules by authoring one or more of the tables in the Registry Tables Group. Many of the benefits of the Windows Installer are lost with self-registration because self-registration routines tend to hide critical configuration information. For a list of the reasons for avoiding self-registration see SelfReg table.

Installation package authors are strongly advised against using the TypeLib table. Instead of using the TypeLib table, register type libraries by using Registry table. If an installation using the TypeLib table fails and must be rolled back, the rollback may not restore the computer to the same state that existed prior to the rollback.

http://msdn2.microsoft.com/en-us/library/bb204770.aspx