I'll add this to my feature ideas list, and donations are always welcome to further support the development and support of the plugin, but I can't promise anything right now.
Now, after checking the WordPress core code again, I think there might be a possibility for you. It is a little bit ugly, as it (currently) requires that you slightly modify a file in WP-Table Reloaded (because there's no filter hook for this), but I guess that you can live with that. You would just have to repeat this modification after WP-Table Reloaded is updated. The necessary change:
In the file "controllers/controller-admin.php", change line 213 to
$this->hook = add_menu_page( 'WP-Table Reloaded', $display_name, $min_capability, $this->page_slug, array( &$this, 'show_manage_page' ), plugins_url( 'admin/plugin-icon-small.png', WP_TABLE_RELOADED__FILE__ ), 9 );
(Note the additional parameter
9 at the end of the line. The "Media" menu item is position
10, so the value
9 should move WP-Table Reloaded before the "Media" item.)
Also, for this to work, your filter above needs to return "admin.php" (or just select "Top-level" in the "Plugin Options", as you won't need the filter then).