point of soul shield tab?

[amas]

Hi, can someone explain to me the importance of the spell shield tab? Here's what it looks like with some of them collected: 

 

 

Now, the part that confuses me is that this page makes it seem like they are something to be collected. They, however, only show up on this page when they are in my inventory. Shields inside storage do not show up on this page.

 

 

 

 

So back to my original question. What's the point? Shields take up so much room and you generally only need a couple sets. Why is there a page dedicated for so many sets if you can not consume or free up space without deleting them?