Problem: I have a table-style View that displays several columns of custom field values. I would like to use a conditional that hides the value in a specific column if the value is identical to the same column in a previous row.

Solution: When the loop is rendered, each iteration has no reference to a previous or future iteration. That means it's not possible to set up a conditional that compares a value from one iteration to a value in another iteration. Instead, you would have to do this with custom CSS and JavaScript. For example, add a custom class to each system-cf cell, and a wrapper span tag like this:

<td class="only-first-system-cf"><span>[wpv-post-field name="wpcf-system-cf"]</span></td>

Then in your custom CSS:

.only-first-system-cf > span {
  display:none;
}
 
.only-first-system-cf.first > span {
  display:inline;
}

Then in your custom JS:

jQuery(document).ready(function(){
  var firsts = [];
  var txt = '';
  jQuery('.only-first-system-cf').each(function(index, item) {
    txt = jQuery(item).text();
    if(firsts.indexOf(txt) == -1){
        firsts.push(txt);
        jQuery(item).addClass('first');
    }
  });
});

Relevant Documentation:
https://toolset.com/documentation/user-guides/digging-into-view-outputs/
https://toolset.com/documentation/user-guides/adding-custom-css-views/
https://toolset.com/documentation/user-guides/adding-custom-javascript-views/
https://api.jquery.com/jquery.each/