These URLs relates to the attachments in your Media Library. WordPress has attachment page of the every image in the Media Library. These can be helpful in driving search engine traffic if you are using sensible (SEO) names of your images.
You can disable them if you are using Yoast SEO plugin. Just follow the simple steps,
Go to SEO > Advanced > Permalinks
Redirect attachment URLs to parent post URL.
OR, you can find alternative plugin by searching in Google like “attachment pages redirect plugin”