You can use this extension: Controlled multi-tab browsing
Go to Chrome Web Store
Set maximum tabs that can be opened and restrict yourself from opening
tabs more than the set limit. The multi-tabbed browsing is good. But
when you find yourself just keep opening too many tabs and using very
few of those, it is not good.
The habit of opening too many tabs may hamper your system performance.
Also, you might waste your time just traversing in between the opened
tabs or managing those using some fancy extension and often learning
nothing. So, I suggest you to keep some well-judged limit on the
number of tabs and to adhere use "Read and Discard" strategy.
Try this extension, set your tab limit and you will really find
yourself learning more by actually using/reading the webpages rather
than just managing and traversing the opened tabs.