Vue by default ships with the v-html directive to show it, you bind it onto the element itself rather than using the normal moustache binding for string variables.
So for your specific example you would need:
<div id="logapp">
<table>
<tbody>
<tr v-repeat="logs">
<td v-html="fail"></td>
<td v-html="type"></td>
<td v-html="description"></td>
<td v-html="stamp"></td>
<td v-html="id"></td>
</tr>
</tbody>
</table>
</div>