Okay…I think I’ve fixed the issue where the first record wasn’t displaying:
<?php if( get_field('specs') ): ?>
<div role="tabpanel" class="tab-pane fade" id="specifications">
<div class="container">
<?php
// vars
$rows = get_field('specs');
$specsheading = get_sub_field('heading');
$specsdescription = get_sub_field('description');
?>
<?php if( have_rows('specs') ): ?>
<table class="table table-striped" border="0">
<tbody>
<?php while( have_rows('specs') ): the_row(); ?>
<tr>
<th scope="row"><?php the_sub_field('heading'); ?></th>
<td><?php the_sub_field('description'); ?></td>
</tr>
<?php endwhile; ?>
</tbody>
</table>
<?php endif; ?>
</div>
</div>
<?php endif; ?>