Hello,
Unfortunately, the only way to adjust columns widths right now is through coding.
If you want to make the change in the code, you need to edit file /modules/CRM/Contacts/Contacts_0.php, at line 69 you need to the following code:
$this->rb->set_header_properties(array(
'dob'=>array('width'=>'100px')
));
You can set more columns, each column is a pair key/value where key is the lowercase name of the field (e.g. first_name) and value is another array with 'width' set to desired width.
At the moment this is I all can recommend really. Unfortunately, modifying this code will make upgrade process slightly problematic.
We have plans to make all the views in EPESI much more adjustable, including display, order, and width of each column. There's no definite ETA on this feature yet.
Kind regards,
Arek