[Dilettante_Pro]

ТС молчит... И таки да - rowIndex

<style>
  button { display:none; }
  tbody tr:hover>td>button {display:inline-block;}
  tbody tr:hover {
    background: #f3bd48; 
    color: #fff; 
   }
</style>
<table id='tbl'>
   <tbody>
   <tr>
      <td>11</td>
      <td>12</td>
      <td>13</td>
      <td><button >Del</button></td>
   </tr>
   <tr>
      <td>21</td>
      <td>22</td>
      <td>23</td>
      <td><button >Del</button></td>
   </tr>
   <tr>
      <td>31</td>
      <td>32</td>
      <td>33</td>
      <td><button >Del</button></td>
   </tr>
   </tbody>
</table>
<script>
[].forEach.call(document.querySelectorAll('button'), function(but) {
    but.onclick = function() {
     var tr= this.parentNode.parentNode;
     tbl.deleteRow(tr.rowIndex);
   }
});

</script>