You need 3 separate loops. One for each row, with each post creating a new column:
<div class="acadp">
<table>
<tr>
<?php while( $acadp_query->have_posts() ) : $acadp_query->the_post(); ?>
<td><?php the_title(); ?></td>
<?php endwhile; ?>
</tr>
<tr>
<?php while( $acadp_query->have_posts() ) : $acadp_query->the_post(); ?>
<td><?php the_content(); ?></td>
<?php endwhile; ?>
</tr>
<tr>
<?php while( $acadp_query->have_posts() ) : $acadp_query->the_post(); ?>
<td><?php the_author(); ?></td>
<?php endwhile; ?>
</tr>
</table>
</div>
<?php wp_reset_postdata(); ?>