Hi  rani,
Check this example. Now please take its reference and correct your code.
HTML
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
    <title></title>
    <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/angular.js/1.5.5/angular.js"></script>
    <script type="text/javascript">
        var app = angular.module('MyApp', []);
        app.controller("MyController", function ($scope, $http) {
            $scope.MyArray = [];
            $scope.Add = function () {
                var customer = {};
                customer.Id = $scope.MyArray.length + 1;
                customer.Name = $scope.Name;
                customer.Country = $scope.Country;
                $scope.MyArray.push(customer);
            };
            $scope.Save = function () {
                $http({
                    method: "POST",
                    url: "WebService.asmx/GetCustomers",
                    dataType: 'json',
                    data: JSON.stringify({ customers: $scope.MyArray }),
                    headers: { "Content-Type": "application/json" }
                }).success(function (response) {
                    alert(response.d + ' record inserted.');
                });
            };
        });
    </script>
</head>
<body ng-app="MyApp" ng-controller="MyController">
    <table>
        <tr>
            <td><input type="text" id="txtName" ng-model="Name" /></td>
            <td><input type="text" id="txtCountry" ng-model="Country" /></td>
            <td><input type="button" id="btnAdd" value="Add" ng-click="Add();" /></td>
        </tr>
    </table>
    <hr />
    <table>
        <tr>
            <td>Id</td>
            <td>Name</td>
            <td>Country</td>
        </tr>
        <tr ng-repeat="customer in MyArray">
            <td>{{customer.Id}}</td>
            <td>{{customer.Name}}</td>
            <td>{{customer.Country}}</td>
        </tr>
    </table>
    <hr />
    <input type="button" id="btnSave" value="Save" ng-click="Save();" />
</body>
</html>
WebService
C#
using System.Collections.Generic;
using System.Web.Services;
/// <summary>
/// Summary description for WebServiceCS
/// </summary>
[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line. 
[System.Web.Script.Services.ScriptService]
public class WebServiceCS : System.Web.Services.WebService
{
    [WebMethod]
    public int GetCustomers(List<Customer> customers)
    {
        foreach (Customer customer in customers)
        {
            // Insert code goes here.
        }
        return customers.Count;
    }
    public class Customer
    {
        public int Id { get; set; }
        public string Name { get; set; }
        public string Country { get; set; }
    }
}
VB.Net
Imports System.Collections.Generic
Imports System.Web.Services
' To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.
<System.Web.Script.Services.ScriptService()> _
<WebService(Namespace:="http://tempuri.org/")> _
<WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)> _
<Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _
Public Class WebServiceVB
    Inherits System.Web.Services.WebService
    <WebMethod()> _
    Public Function GetCustomers(ByVal customers As List(Of Customer)) As Integer
        For Each customer As Customer In customers
            ' Insert code goes here.
        Next
        Return customers.Count
    End Function
    Public Class Customer
        Public Property Id As Integer
        Public Property Name As String
        Public Property Country As String
    End Class
End Class
Screenshot
