Quick Edit Pencil is used for editing your post faster without through the dashboard. If you want to add it, go to Dashboard, then click Design, then switch the tab to 'Edit HTML', don't forget to check Expand widget templates box. Back-up your template first by download it which the option is available on the same page.
To add the Quick Edit Pencil, search the following code on your recent template.
<b:includable id='postQuickEdit' var='post'>
<span expr:class='"item-control " + data:post.adminClass'>
<a expr:href='data:post.editUrl' expr:title='data:top.editPostMsg'>
<img alt='' class='icon-action' src='http://www.blogger.com/img/icon18_edit_allbkg.gif'/>
Easily, you can search that code on by using your Browser Search (usually by pressing CTRL + F) and search this code so you can find those code above:
b:includable id='postQuickEdit' var='post'
If you find that code, it means you are in the halfway of adding Quick Edit Pencil. But if you don't see that code, it means you need to copy/paste it just before this code:
<b:includable id='comments' var='post'>
And make sure this following code is available on your template:
<div class='post-footer-line post-footer-line-1'>
<b:include data='post' name='postQuickEdit'/>
Just before this code which is located on your post footer code:
Save the template and see.