Thanks for your update with the additional information and the contents of your template. I entered your shortcode and template in my system and it is working there.
First, make sure you have the closing “‘>” on your Open: section. Your post does not show it:
Open: <table id='[+selector+]' class='gallery galleryid-[+id+]
To make sure your template is actually being used, you can try changing the Open: section to:
<h3>My PDF Table</h3>
<table id='[+selector+]' class='gallery galleryid-[+id+]'>
Here are a couple of additional suggestions you can try:
Change your shortcode to:
[mla_gallery columns=1 post_mime_type=application/pdf post_parent=all link=file size=icon mla_markup=pdf-table]
You don’t need the mla_caption= parameter because you can use the template to control the content. You don’t need the “enclosing shortcode” format, either. Of course, it is harmless and a matter of style.
Change the “Item:” section of your template to:
<td class='gallery-icon'>
[+link+]
</td>
<td class='wp-caption-text gallery-caption'>
[+title+]
</td>
On my system, that gets the PDF icon as a link to the file, and the document Title to the right of each icon. If it’s not working for you, your theme may be using the class= attributes in some way. Try removing the class='wp-caption-text gallery-caption' portion of the <td> tag to see if that helps.
You can also try changing the [+title+] value to a literal value such as “The Title should be here!” just to see if that shows up in the output.
If you’re still having trouble perhaps you can post a link to one of your pages so I can check out the HTML source code being generated.
Let me know if the above suggestions are helpful. Thanks for your patience.