How to return and read muliple DataTable using JQuery AJAX in ASP.Net

if (customers.length > 0) {

            $.each(customers, function () {

                var customer = $(this);

                $("td", row).eq(0).html($(this).find("ContactName").text());

                $("td", row).eq(1).html($(this).find("CustomerID").text());

                $("td", row).eq(2).html($(this).find("City").text());

                $("[id*=gvCustomers]").append(row);

                row = $("[id*=gvCustomers] tr:last-child").clone(true);

            });

 

 

Conclusion append two Lines for single record due to repeation in loop.... Actually I have two tables for a payroll project

Addition and Deduction i am Searching the record as they typed in textbox It  is working on Addition but we i joined then in SP so resulting repeating aftermath I had to alter addition table and add deduction columns to complete the work but Still problem here that why is not working for two tables...