You need to do some modify at controller and layout file:

Action file look like:

namespace{YourClassNameSpace};


use Magento\Framework\App\ResponseInterface;
use Magento\Framework\Controller\ResultFactory;

class {YourClassname} extends \Magento\Framework\App\Action\Action
{

............
..............

    public function execute()
    {

        $resultLayout = $this->resultFactory->create(ResultFactory::TYPE_LAYOUT);
        return $resultLayout; 
    }
}

Now,you have add root container at your layout file booking_index_ajax.xml :

<?xml version="1.0"?>
<layout xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/layout_generic.xsd">
    <container name="root">
       <block class="Mymodule\Booking\Block\BookingList"
                   name="test.booking.filtertable"
                   template="Mymodule_Booking::content/test.phtml"
                   />
    </container>
</layout>

/////////

You need to do some modify at controller and layout file:

Action file look like:

namespace{YourClassNameSpace};


use Magento\Framework\App\ResponseInterface;
use Magento\Framework\Controller\ResultFactory;

class {YourClassname} extends \Magento\Framework\App\Action\Action
{

............
..............

    public function execute()
    {

        $resultLayout = $this->resultFactory->create(ResultFactory::TYPE_LAYOUT);
        return $resultLayout; 
    }
}

Now,you have add root container at your layout file booking_index_ajax.xml :

<?xml version="1.0"?>
<layout xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/layout_generic.xsd">
    <container name="root">
       <block class="Mymodule\Booking\Block\BookingList"
                   name="test.booking.filtertable"
                   template="Mymodule_Booking::content/test.phtml"
                   />
    </container>
</layout>

You need to do some modify at controller and layout file:

Action file look like:

namespace{YourClassNameSpace};


use Magento\Framework\App\ResponseInterface;
use Magento\Framework\Controller\ResultFactory;

class {YourClassname} extends \Magento\Framework\App\Action\Action
{

............
..............

    public function execute()
    {

        $resultLayout = $this->resultFactory->create(ResultFactory::TYPE_LAYOUT);
        return $resultLayout; 
    }
}

Now,you have add root container at your layout file booking_index_ajax.xml :

<?xml version="1.0"?>
<layout xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/layout_generic.xsd">
    <container name="root">
       <block class="Mymodule\Booking\Block\BookingList"
                   name="test.booking.filtertable"
                   template="Mymodule_Booking::content/test.phtml"
                   />
    </container>
</layout>

You need to do some modify at controller and layout file:

Action file look like:

namespace{YourClassNameSpace};


use Magento\Framework\App\ResponseInterface;
use Magento\Framework\Controller\ResultFactory;

class {YourClassname} extends \Magento\Framework\App\Action\Action
{

............
..............

    public function execute()
    {

        $resultLayout = $this->resultFactory->create(ResultFactory::TYPE_LAYOUT);
        return $resultLayout; 
    }
}

Now,you have add root container at your layout file booking_index_ajax.xml :

<?xml version="1.0"?>
<layout xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
xsi:noNamespaceSchemaLocation="urn:magento:framework:View/Layout/etc/layout_generic.xsd">
    <container name="root">
       <block class="Mymodule\Booking\Block\BookingList"
                   name="test.booking.filtertable"
                   template="Mymodule_Booking::content/test.phtml"
                   />
    </container>
</layout>

/////////