Allysistemas: Php - Arreglos sencillos

$user_data = [];
$user_data['name'] = 'Steve Wozniak';
$user_data['age'] = 65;
$user_data['compnay'] = 'Apple';
$user_data['availability'] = true;

$famous_tech_people[] = [
    'name' => 'Steve Jobs',
    'address' => 'Cupertino, CA',
    'availability' => false,
    'email' => 'steve@apple.com'
 ];
 $famous_tech_people[] = [
    'name' => 'Bill Gates',
    'address' => 'Reston, VA',
    'availability' => true,
    'email' => 'bill@ms.com'
 ];

          <tbody>
            <tr>
              <td><?php echo $famous_tech_people[0]['name'] ?></td>
              <td><?php echo $famous_tech_people[0]['address'] ?></td>
              <td><?php echo $famous_tech_people[0]['email'] ?></td>
              <td><?php echo $famous_tech_people[0]['availability'] ? 'Si' : 'No' ?></td>
            </tr>
            <tr>
              <td><?php echo $famous_tech_people[1]['name'] ?></td>
              <td><?php echo $famous_tech_people[1]['address'] ?></td>
              <td><?php echo $famous_tech_people[1]['email'] ?></td>
              <td><?php echo $famous_tech_people[1]['availability'] ? 'Si' : 'No' ?></td>
            </tr>
          </tbody>

proviniendo de un formulario

$name = isset( $_POST['name'] ) ? $_POST['name'] : ''; 

$email = isset( $_POST['email'] ) ? $_POST['email'] : ''; 

$message = isset( $_POST['message'] ) ? $_POST['message'] : '';

echo "Hola {$name}, tu correo es {$email}, tu mensaje es {$message}";