Twilio developer evangelist here.
You can get the list of numbers on your account by calling the Incoming Phone Numbers list resource. This is done in PHP, using the Twilio PHP helper library, like this:
<?php
// Get the PHP helper library from twilio.com/docs/php/install
require_once('/path/to/twilio-php/Services/Twilio.php'); // Loads the library
// Your Account Sid and Auth Token from twilio.com/user/account
$sid = "{{ account_sid }}";
$token = "{{ auth_token }}";
$client = new Services_Twilio($sid, $token);
// Loop over the list of numbers and echo a property for each one
foreach ($client->account->incoming_phone_numbers as $number) {
echo $number->phone_number;
}
I'll leave it to you to turn that into the HTML output you need.
Let me know if this helps.