Are multiple Links in HTML5 Ad for Adwords possible?

yes, you just need to have 3 different coded buttons with links to them. That should work. 

Clicking on the specified symbol instance loads the URL in a new browser window.

Instructions:
1. Replace http://www.adobe.com with the desired URL address.
Keep the quotation marks ("").
*/

this.btn1.addEventListener("click", fl_ClickToGoToWebPage);

function fl_ClickToGoToWebPage() {
window.open("http://www.adobe.com", "_blank");
}

/* Click to Go to Web Page
Clicking on the specified symbol instance loads the URL in a new browser window.

Instructions:
1. Replace http://www.adobe.com with the desired URL address.
Keep the quotation marks ("").
*/

this.btn2.addEventListener("click", fl_ClickToGoToWebPage_2);

function fl_ClickToGoToWebPage_2() {
window.open("http://www.adobe.com", "_blank");
}

/* Click to Go to Web Page
Clicking on the specified symbol instance loads the URL in a new browser window.

Instructions:
1. Replace http://www.adobe.com with the desired URL address.
Keep the quotation marks ("").
*/

this.btn3.addEventListener("click", fl_ClickToGoToWebPage_3);

function fl_ClickToGoToWebPage_3() {
window.open("http://www.adobe.com", "_blank");
}