textfield

how you add a text area which you can have default values for example

[
    {
        "product_id":10,
        "weight":"1",
        "length":"1200",
        "width":"20",
        "height":"300",
        "customer_postcode":"8021"
    },
    {
        "product_id":37,
        "weight":"12",
        "length":"12300",
        "width":"2340",
        "height":"3010",
        "customer_postcode":"8021"
    }
]

Is there any parameter to add a text area?