Hello Rob,
this is not possible at the moment.
You need to delete the column manually by editing the file "components/com_jvotesystem/views/polls/tmpl/default_table.php". Remove the
<th><?php echo JText::_("Author")?></th>
tag and the line
<td nowrap="nowrap"><a class="author" href="<?php echo $this->general->buildLink("user", $poll->autor_id);?>" data-u="<?php echo $poll->autor_id;?>"><?php echo $author->name;?></a></td>
I will maybe add an option for that in further versions.
Best Regards,
Johannes Meßmer