Not sure if I got well your first questions (associate a description…). Would you mind to be more specific (a screenhot would help).
This is what I understood, you want a description field for each attachemnt you add to the item. If tha's the case the answer is no but you can
use a field of the item to capture the description for each attachment.
For the second part, yes you can, open ezEdit, go to Form Layout and then select TabLayout, then define at least 2 tabs there.
Then go to the Displayed fields section and place the field Attachments to the tab you want.