For example, we want to open 2 URLs (http://google.com and http://yahoo.com) in a different tab with one link click. You can do it in 2 ways defining in a tag or using JavaScript.
But in both cases, you have to use a window.open method.
Open multiple tabs with one link Examples
Here is a basic implementation in JavaScript-
<html>
<body>
<a href="#" onclick="window.open('http://google.com');
window.open('http://yahoo.com');">Click to open Google and Yahoo</a>
</body>
</html>
Window open method in HTML tag
<!DOCTYPE HTML>
<html>
<body>
<a href="#" onclick="yourlink()">Click Here</a>
<script>
function yourlink() {
var locs = ['http://google.com', 'http://yahoo.com']
for (let i = 0; i < locs.length; i++) {
window.open(locs[i])}
};
</script>
</body>
</html>
Output:

Note: Unblock the pop-up windows for your browser and the code could work.
Do comment if you have any doubts or suggestions on this HTML topic.
Note: The All HTML Examples codes are tested on the Firefox browser and the Chrome browser.
OS: Windows 10
Code: HTML 5 Version

Degree in Computer Science and Engineer: App Developer and has multiple Programming languages experience. Enthusiasm for technology & like learning technical.
Is there any way that the user does not need to do the unblock the popup windows for the browser and still multiple tabs could open?
Thanks in advance.