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>
    <alltransclusions gatcontinue="BPSlots3|3338" />
  </query-continue>
  <query>
    <pages>
      <page pageid="3339" ns="10" title="Template:BPSlots1" />
      <page pageid="3340" ns="10" title="Template:BPSlots2" />
      <page pageid="5638" ns="2" title="User:DavidAHare/BelowVLvL Pack" />
      <page pageid="5640" ns="2" title="User:DavidAHare/ItemSets Pack" />
      <page pageid="5896" ns="2" title="User:DavidAHare/ItemSets" />
      <page pageid="5911" ns="2" title="User:DavidAHare/Giggles Set" />
      <page pageid="5912" ns="2" title="User:DavidAHare/Khale Set" />
      <page pageid="6802" ns="2" title="User:DavidAHare/Game Backpack1" />
      <page pageid="6803" ns="2" title="User:DavidAHare/Game Backpack2" />
      <page pageid="6805" ns="2" title="User:DavidAHare/Armory" />
    </pages>
  </query>
</api>