Hi @Songpol
To understand how Extract DataTable works, see below video for refernce:
https://youtu.be/QllyIdxm4H0?feature=shared
Also for example, i am using a website which is having radio buttons in the table :
https://codepen.io/henrijeret/pen/ExNRNOR

Here, i am trying to select the radio buttons under Preserve columns.
So first i extracted all rows of that table using extract data from webpage and store in datatable.
Next i used click radio button action to click the required radio button, But in selector, i have designed in such a way that it should select last row and preserve column , so after some tryouts i got the selector like below

Flow design used:
