module – How to create a custom product attribute where i can upload as many PDFs as needed, and upload the thing as a whole?

I need to complete a task which i have been struggling with since last week.
If i “Go to Seller Store” and then into editing a product (both a new product or one that is already uploaded), in the attributes section i have this:

enter image description here

Not only it looks bad (i cant manage to deal with the bootstrap classes so that the white spaces dissapear), but its not practical.. What i need is something like this:

enter image description here

Bassically. Instead of being separate inputs, i need to be able to “Add or Remove” the inputs based on how many PDFs i need to upload, and then have only one button to let me upload all my documents.
Is this possible? How can i do it as close as the example in the second picture as possible.
Thank you very much.