Hello Nishit thank you for your message, if the page does not take PHP code that’s all fine please focus on the task and then see what areas can be customizable by admin. It is however keep codding that way so we can make this page editable by doing this way you will be prepared if any similar tasks arise in the future.
FOR YOUR Query : Do you want to display all Numbers or the Number selector drop-down like display in task screen shot(https://webmaklay.com/wp-content/uploads/2022/08/Table.jpg)? – it is a customer information page and only customers phone numbers should be there. For multiple numbers display i would rather stick to the screen from site admins.