Thanks for the info.
The reason that I am trying to use the Custom Table under the Tools is that I can create templates and store different values under each template. The templates are not linked to the document until it is loaded and attached to the part. In this case, I can choose and load a set of data that best matches the part. That saves considerable time.
Custom Properties under File, on the other hand, can achieve the same objective. However, I would have to create various document templates to store different sets of data, and it is more time consumming if I want to change the data set in mid stream of design. In addition, all the selection would have to be lump in one page (Custom Properties page).
If there is a better way to achieve what I want to do, please let me know. Thanks!