'Clear All' button for clearing all open tabs in trash doesnt work on macos (sierra)
That's on my top reason why I haven't use vivaldi as my main browser. I happen to have many tabs open (>30). The 'clear all' button at the bottom on the left sidebar never worked me. Even closing manually each tab (clicking 'x') when you have more than >30 tabs open is extreeeemely slow
The trash icon only holds recently closed tabs in its current iteration. If you want to view/handle open tabs anywhere else but in the tab bar you will need to use an extension for now.
There is a better way to close that many tabs. Just click on the outmost one you want to close, hold shift (command for single tabs) and click to select all the other tabs at once. They have a blue outline now and you can close them with right click menu. There is also an option to close all tabs to the left or to the right of a currently selected tab.
@pzo I'm not sure if this is an option for you but instead of resuming your previous session, your can have Vivaldi "start fresh" and launch with either its "Start Page" or a web site of your choice. You can configure this in the Startup section of the Vivaldi preferences.