DocType Field default value

Hi all,
I need to create a Table field into a document and preload in table a subset of data.

Is it possible to using Default option under the definition of the field into custom form?

Not an easy hack, but off course you can do this with minimum coding.
check Taxes on Charges Template code.

refer following code, you will get some idea.

let me know, if you find any issue while writing this.