Confused with Mustache lang and Template

1

I get all keys of my array on the left column instead of each one at every raw consecutively.

56

Instead, I would like to have this below, how can I do it.

        attack 	decay 	sustain 	release 	gain   	frequency
pt 	3.59408 	3.59408 	3.59408 	3.59408 	3.59408 	3.59408
eta 	-1.50158 	-1.50158 	-1.50158 	-1.50158 	-1.50158  -1.50158
phi 	0.785895 0.785895 0.785895 0.785895 0.785895 0.785895
charge 	    -1 	    -1 	    -1 	    -1 	    -1 	    -1

So pt, eta etc. are appearing in my table one by one, and not all in every row.

Here is my HTML

 <th>
                {{#each key in dataKeys}}
                {{key}}
                {{/each}}
            </th>

Function to get keys of my array:

function getKeys() {
        var keys = event.map( items => Object.keys(items) );
        return keys;
    }

And helper:

 'dataKeys': function(key){
            return getKeys();
        }