This doesn't seem to be a question for FileMaker Server....
If you select all the fields you want to size the same, you can use resize button on the Arrange and align section of the Inspector's Position tab to give all fields the same width as the widest or narrowest field. You can also use another control here to align the left, right or centers of the fields to clean them up.
Hmm, but I wonder if you should have all those separate fields in the first place. The arrangment of these fields and their field names suggest that you should be using a table where you have one record for each row of fields instead of all these separate fields. Such a set of records can be put in a related table and displayed with a portal or the records can be displayed on a list or table view layout.