This can be done with Javascript on the Classic Designer.  This was tested in Forms version 11.0.2212.30907.

There are a couple items we need to address:

1. The archived version of the form will end up with much of your table hidden if we do this.  In your case, you've said this form won't be submitted, so that shouldn't be an issue.  But if you do this on a form that can be archived, you need to be able to address that to ensure the form is handled differently, or make an alternate version of the form for archival.
    
2. The column widths set on the Layout page are percentages, but to have a table that can scroll, we need these to be fixed values.  Unfortunately, there isn't a way to set fixed values on the Layout page, so we need to address this in the Javascript.  Here's how:
    
   • If we want all of the columns to be the same width (let's say 150px), then we can do that fairly easily using Javascript like this (your table will need the scrollingTable class to be assigned to it).  This script loops through all of the column headers and sets their width to 150px, and then modifies the CSS of the table to allow overflow (which is where the scrolling comes in). 

     $(document).ready(function () {  
       $('.scrollingTable thead th').each(function() {   
         $(this).css('width', '150px');
       });
       $('.scrollingTable .cf-table_parent').css('overflow', 'auto');
     });

     
      
   • If we want different column widths, then we need to do this for each column.  The easiest way to do that is via the "q0" id value for each field, since that exists on the header where we need to set the width (your table will need the scrollingTable class to be assigned to it).  This script loops through each of the column headers and sets their values based on their "q0" id value, or to 100px if their ID wasn't specifically listed (this is good if most of the columns are the same width, and only some need to be wider).  After changing their widths it modifies the CSS of the table to allow overflow (which is where the scrolling comes in).

     $(document).ready(function () {  
       $('.scrollingTable thead th').each(function() {   
         if($(this).attr('id') == 'q1') { $(this).css('width', '150px'); }
         else if($(this).attr('id') == 'q2') { $(this).css('width', '200px'); }
         else if($(this).attr('id') == 'q3') { $(this).css('width', '250px'); }
         else if($(this).attr('id') == 'q4') { $(this).css('width', '300px'); }
         else if($(this).attr('id') == 'q5') { $(this).css('width', '350px'); }
         else if($(this).attr('id') == 'q6') { $(this).css('width', '400px'); }
         else if($(this).attr('id') == 'q7') { $(this).css('width', '500px'); }
         else { $(this).css('width', '100px'); }
       });
       $('.scrollingTable .cf-table_parent').css('overflow', 'auto');
     });