A family of Microsoft word processing software products for creating web, email, and print documents.
Not simple, but you could use Jay Freedman's AutoCorrect backup / restore utility AutoCorrect2007.
The Restore would need to be run on each user's computer but will not overwrite their entries unless there is a conflict. This works with both formatted and unformatted entries.
You would want only your new entries in the table.
When asked if you wanted to delete entries, say no.
The Macro Zone - Jay Freedman, MVP
Note that if you could, instead, use Building Blocks / AutoText, it is much easier to add these globally by distributing a Global Template (.dotx or .dotm) containing the building blocks.