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="Bench_7_fit.PNG" />
  </query-continue>
  <query>
    <pages>
      <page pageid="2008" ns="6" title="File:BB.png" />
      <page pageid="2579" ns="6" title="File:BER AB.jpg" />
      <page pageid="2578" ns="6" title="File:BER AB.rar" />
      <page pageid="2592" ns="6" title="File:BER Eve.rar" />
      <page pageid="4765" ns="6" title="File:Ball bearing motor model one.png" />
      <page pageid="4579" ns="6" title="File:Baltic.png" />
      <page pageid="2932" ns="6" title="File:Basic EVA.jpg" />
      <page pageid="2923" ns="6" title="File:Basic Work Breakdown.jpg" />
      <page pageid="1803" ns="6" title="File:Beaufort BL 3.png" />
      <page pageid="1804" ns="6" title="File:Beaufort BL 7.png" />
    </pages>
  </query>
</api>