If you have the same tabs open all the time, like a tab for your email, calendar, or whatever else that's useful to have on hand while you're working at your computer, you can pin the tab so it sticks on your browser, even after you close and reopen Chrome.
And just like that, your tab is pinned. It becomes smaller compared to unpinned tabs and sticks to the left of the tab row in Chrome. If you want to unpin the tab, right click it and select "Unpin Tab."
Apple announced at this year's WWDC that the new Safari in the new Mac OS X El Capitan will also feature pinned tabs.
If you want to quickly close all tabs apart from one, right click on the tab you want to keep, and select "Close Other Tabs." Every tab apart from those that are pinned will close.
If you want to keep two or more tabs but want to quickly delete the others, click and drag those you want to keep to the left of the tab row. Then right click the last tab you want to keep with the unwanted tabs to its right and click "Close Tabs to the Right." The tabs you want to keep on the left will remain while all the tabs on the right of the tab you right clicked will close.
If you accidentally closed a tab, right click on any tab and select "Reopen Closed Tab." It will open a new tab with the last one you closed. Keep doing this to bring up multiple closed tabs in the reverse order that you closed them.
If you have too many tabs but you don't necessarily need them at the moment and you want to keep them for reference later, quickly put them in a bookmark folder by right clicking any tab and selecting "Bookmark All Tabs." A window will pop up asking you to name the folder. Click Bookmarks Bar in the list below the title, then click Ok. You'll see a new folder appear in the bookmarks toolbar with all the open tabs you had, including pinned tabs.
You can then close all those tabs to start surfing with a fresh browser window.
And by the way, those pictures in the background is Google's Art Project extension called Google Cultural Institute, and it shows new art every time I open a new tab.
The Google Cultural Institute extension is set to change the art work once a day by default, but you can go into the extension's settings and set it to change artwork every time you open a new tab.