I have to represent my data like this, on a suitelet. while I can do the rest, I am confused about button that will select the corresponding details on sales order. Any guidance would be appreciated.

We cannot add the button on the sublist. You will have to create this whole table using inline html field. You can add the button in the inline html itself and show the button like this. In the Inline HTML you will also have to add the script tag for the onclick listner of button click.

This table is not static, this can contain any number of rows max (25.) How will I do that, and custom function for every button @Nikhil Gangji

The Inline HTML default code will keep on changing depending on the number of rows. If you have multiple rows then you can create the script tag using the for loop and add the onclicks accordingly.