Hello Dubsteplpad
These are your web data saved. If you delete them sometime make you trouble to search on the web next time. But if you really to remove that can go to Setting on iPhone or sign in the Google and search history choose recovery data website, you can delete from here and your iPhone will be cleared later. This action help your Storages no more full in use better but Remember that next time you on web online that slowly a little. After few times it’s will came back normal. Don’t worry
Thanks and regard