JSFiddle - React, Tailwind, and code Playground

HTML

<table>
   <tr>
       <td>
         <input class='quantity' value=''/>
         <input class='100' value=''/>
       </td>
       <td>
         <input class='quantity' value=''/>
         <input class='50' value=''/>
       </td>
       <td>
         <input class='quantity' value=''/>
         <input class='20' value=''/>
       </td>
   </tr>
   <tr>
       <td>
         <input class='quantity' value=''/>
         <input class='100' value=''/>
       </td>
       <td>
         <input class='quantity' value=''/>
         <input class='50' value=''/>
       </td>
       <td>
         <input class='quantity' value=''/>
         <input class='20' value=''/>
       </td>
   </tr>
</table>

JavaScript

var $quan = $('.quantity');
$quan.on('keyup', function(e) {
    if (e.which === 13) {
        var ind = $quan.index(this);
        $quan.eq(ind + 1).focus()
    }
});