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>
    <allfileusages gafcontinue="Bandos_chestplate_upg.png|618" />
  </query-continue>
  <query>
    <pages>
      <page pageid="627" ns="0" title="Bandos boots" />
      <page pageid="1943" ns="0" title="Balfrug Kreeyath" />
      <page pageid="2583" ns="0" title="Bandit" />
      <page pageid="2827" ns="0" title="Book of balance" />
      <page pageid="3857" ns="0" title="Baby black dragon" />
      <page pageid="3860" ns="0" title="Baby red dragon" />
      <page pageid="4292" ns="0" title="Bandit champion" />
      <page pageid="5439" ns="0" title="Bandos body" />
      <page pageid="5440" ns="0" title="Bandos chaps" />
      <page pageid="6200" ns="0" title="Baby Blue Dragon" />
    </pages>
  </query>
</api>