I use a safari extension called "Tab Space" this gives me the ability to close all tabs to the right or left of my currently active tab.
They use Ctrl + R and Ctrl + L for this and i find this super useful.
I'll leave the Tab Space settings for reference
Just wanted to say that the extension "LetMeWatch" which is used for watching movies + series is not currently working in the browser.
It does install, it lets you search for a specific movie or series but when opening the link the webpage keeps flashing.- In Tab overview
Tab overview.