You are looking at the HTML representation of the XML format.
HTML is good for debugging, but is unsuitable for application use.
Specify the format parameter to change the output format.
To see the non HTML representation of the XML format, set format=xml.
See the complete documentation, or API help for more information. 
<?xml version="1.0"?>
<api>
  <query-continue>
    <allimages gaicontinue="Tafel_1_Algerien_Num.png" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1003" ns="6" title="Datei:Tabelle 12 AT.png" imagerepository="local">
        <imageinfo>
          <ii timestamp="2015-03-26T15:20:17Z" user="Ederieker" />
        </imageinfo>
      </page>
      <page pageid="1004" ns="6" title="Datei:Tabelle 13 AT.png" imagerepository="local">
        <imageinfo>
          <ii timestamp="2015-03-26T15:20:43Z" user="Ederieker" />
        </imageinfo>
      </page>
      <page pageid="1002" ns="6" title="Datei:Tabelle 14 neu.png" imagerepository="local">
        <imageinfo>
          <ii timestamp="2015-03-26T15:05:50Z" user="Ederieker" />
        </imageinfo>
      </page>
      <page pageid="968" ns="6" title="Datei:Tabelle 15 AT neu deutsch.png" imagerepository="local">
        <imageinfo>
          <ii timestamp="2015-03-25T17:37:35Z" user="Ederieker" />
        </imageinfo>
      </page>
    </pages>
  </query>
</api>