The New Tab page in Google Chrome is what you see when you open a new tab in Google Chrome, it's designed to get you to your favorite apps and sites, as quickly as possible. It defaults to thumbnails of the nine most visited web pages you have browsed, you can just click a thumbnail to visit the site. Many users love this feature as you can quickly return to the websites you most often visit. If you want to remove these most visited thumbnails from your Google Chrome new tab page, please follow the steps below.
You can also install Click&Clean extension. This security extension deletes your browsing history, typed URLs, Flash cookies, all traces of your online activity to protect your privacy.
How to remove thumbnails from Google Chrome most visited web pages