can be configured to start with multiple homepages, but this type of setup has a major drawback — opening multiple webpages at the same time may slow down your browser's operation. Fortunately, Opera offers a simple way to remedy this issue.
How To Stop Opera from Loading Background Tabs
Click on the Opera
> Advanced settings
and then tick the Show advanced settings
Go to the On startup
section and then tick the Delay loading of background tabs
While setting is enabled, Opera
won’t load background tabs unless you click on them.