For "Related Products" TAB - How to list several products at one time.

For each listing in my Bulletin Boards category, I have developed a “Related Products” tab. (which are my matching Decorative Push Pins for each fabric). How can I list more than one product at a time. I am using …my listing>blocks>add products… It seems like I have to add one product at a time. I have as many as 8 or 10 matching products that the customer may like for the fabric they have chosen. (I have over 600 fabrics). Thanks, Diana