To access the approver of the current workflow step, use:

$workflowHistory.activeStep.executedByNames$

If you want to have a list of all approvers of a quote, you can iterate through the workflow history steps with the code below:

<table>
<tr>
<th  align = "left">Workflow comments:</th>
</tr>
$workflowHistory.steps: { step |
<tr>
  $if(step.executedByNames)$
    $if(step.comment)$
      <td>Step: $step.uniqueName$, Executed By: $step.executedByNames$, Reason: $step.comment$</td>
    $else$
      <td>Step: $step.uniqueName$, Executed By: $step.executedByNames$, Reason: N/A</td>
    $endif$
  $endif$

</tr>
}$

</table>

The above code will look like this in a workflow email: