Well, since html elements already have a querySelectorAll function, you could just assign it to a new method "qsA":

    HTMLElement.prototype.qsA = HTMLElement.prototype.querySelectorAll; 

Now myTable.qsA('tr') will work. You can try it right here on the HN page in the browser console:

    HTMLElement.prototype.qsA = HTMLElement.prototype.querySelectorAll; 
    document.querySelector('#hnmain').qsA('tr'); 

Why do you prefer chaining?