1. for the drop down menu i can run over the list and write the tag <option> inside the loop? it will create the menu with the number of items in the list? there is another way?

2. i am planning to build the table the same way with a loop.
but i want to know how can i get a selected row from the table.
if i have a link in every row how can i know which row was selected?

Yes there can be other ways, but in this case it is most simplest and efficient way

Not sure what you are attempting to do, but you can provide each row tag "tr" with unique id and use jQuery to handle clicks and return selections. Or there is always option of using buttons/checkboxes/radioboxes for each row. As I said, not knowing your requirements makes it difficult to advice

Correct me if I'm wrong, but aren't data in the table first populated by servlet?
If it so then you have some unique IDs you can reuse for creating links with call for servlet plus additional parameter which in this case would be some unique ID, for example book shop would use ISBN as this unique and hyperlink would be as "www.bookshop.com/ServletCall.jsp&itemId=1234"

I am sorry for replying to this, but shouldn't it be like this:
"www.bookshop.com/ServletCall.jsp?itemId=1234"
instead of a '&'