Using CSS for Varying Width of Columns

I have installed the Gravity Forms Directory and have generated a page at:

http://www.wpcc.edu/wpcc_2/directory

I am trying to add CSS somewhere in the process to format the table that displays the entries. I want control over the widths of the 5 columns so I can format the output more attractively. I’m wanting to shrink the far right column’s width (along with the width of columns 3 and 4) so I can expand columns 1 and 2 to pull together names into one line and the telephone numbers into one line.

I want to set the table to 100% width on the page, then let the 5 columns resize themselves via percentages within this 100% layout.

Any help or ideas you can provide is greatly appreciated!

https://wordpress.org/plugins/gravity-forms-addons/