Your problem has nothing to do with Knockout:
you have self-closed your select tag which results in invalid HTML so the browser interprets your span as the content of the select.
To fix this just properly close your select with </select>:
<tr>
<td data-bind="i18nTranslateText: 'abc'"></td>
<td>
<select style="width: auto;" data-bind="options: pqr, value: abc.xyz" >
</select>
<span data-bind="i18nTranslateText: 'Minutes'"></span>
</td>
</tr>