Is it possible to change the width of the attachment column?
I don't thing so, but why would you?
It is not possible to change the width of the attachment column. Are you only seeing part of the column (is the attachment icon cut off)? It may be that you are not scrolled all the way over to the left. Using your trackpad/mouse, try scrolling all the way to the left of your sheet to see the entire attachments column.
Oh my goodness, I don't know why I struggled with this but you saved me some grief. I couldn't figure out why I wasn't able to access that column.