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="Bandwidth_utilization_SNMP.pdf|4304" />
  </query-continue>
  <query>
    <pages>
      <page pageid="1540" ns="0" title="SNBI Architecture and Design" />
      <page pageid="1810" ns="0" title="BGP LS PCEP:BGP" />
      <page pageid="3945" ns="0" title="BGP LS PCEP:Beryllium Developer Guide" />
      <page pageid="4878" ns="180" title="Project Proposals:BIER Plugin" />
      <page pageid="6866" ns="180" title="Project Proposals:BIER APP" />
      <page pageid="16145" ns="0" title="Dashboard Kibana" />
    </pages>
  </query>
</api>