Found the easiest way to do this. Works even with div!
<div onclick="downloadFiles()">
<!--do not put any text in <a>, it should be invisible-->
<a href="path/file1" id="a1" download></a>
<a href="path/file2" id="a2" download></a>
<a href="path/file3" id="a3" download></a>
<script>
function downloadFiles() {
document.getElementById("a1").click();
document.getElementById("a2").click();
document.getElementById("a3").click();
}
</script>
Download
</div>
That's all, hope it helps.