Many technical pages in the index

Hello. Our site inoxoft.com has a lot of technical pages in the index. In general, there are separate pages for images. And there are about 350 pages were indexed, and it's not good at all.
We can't close them in robots.txt because they don't have similar fragments in the URL, also, we can't close wp-content, where all images are saved.
We add meta noindex nofollow to every page, but it's still all in the index.

Do you have any idea, where they come from and how much time is required to delete these pages from the index?

 

You can enter the list of URLs that shouldn't be indexed into the robots.txt I think it wouldn't be too large after that.

 

It's almost 400 pages in the index. I don't think it's a good idea to put them all in robots

 

Create a separate directory to those pages if they are related to one category or if they belong to different categories like images, webpage or other then create a separate directory to those and block the whole directory in the robots.txt file, using nofollow and noindex tag in every webpage not seem fine for the SE.

 

thank you for advice.
why it's not good for SE? because it would be very suspected for it?