Width of cells are not a part of styles, nor can it be updated automatically when linked files are changed.
There is also no link between the width in Excel to the width in InDesign.
Maybe that some 3rd party developers have some data base connection plugins developed which can handle this problem, but I am not aware of any.
This script was posted here a long time ago - it allows saving of column widths in table styles. They don't directly apply, but they can be applied with the script.
Thanks for the responses, I can see I need to clarify my question.
We have imported formatted excel tables into ID and the updated data updates with no problem. When we change the column width in excel -- they never update in the ID file. Update doesn't seem to recognize changes in column width.
We've got about 50 tables and I have been asked to keep the tables exactly as they are in excel without applying table styles once they are placed in ID.
If they must be exact, the only way to do that is to create PDFs of the Excel spreadsheet and place them in InDesign. You can then create new PDFs overwriting the old ones and update the link that way.