how to access html table td values to codebehind?

$(function () {
        SetEmptyMessage();
        $("[id*=cbSelect]").on("click", function () {
            var selected = $('[id$=gvCompanyListing] tr td input[type=checkbox]:checked');
            if (selected.length > 0) {
                $(selected).each(function () {
                    var appendRow = $(this).closest('tr').clone(true);
                    var row = $(this).closest('tr');
                    $(row).remove();
                    $("[id$=tblAssigned]").append(appendRow);
                });
                SetEmptyMessage();
                return false;
            }
            else {
                var selected = $('[id$=tblAssigned] tr td input[type=checkbox]:not(:checked)');
                if (selected.length > 0) {
                    $(selected).each(function () {
                        var appendRow = $(this).closest('tr').clone(true);
                        var row = $(this).closest('tr');
                        $(row).remove();
                        $("[id$=gvCompanyListing]").append(appendRow);
                    });
                }
                SetEmptyMessage();
                return false;
            }
        });
    });

    function SetEmptyMessage() {
        if ($('[id$=tblAssigned] td').closest('tr').length == 0) {
            //var colspan = $('[id$=gvAssigned] th').length;
            //$('[id$=tblAssigned]').append('<tr class="empty"><td colspan=' + colspan + '>No records were found</td></tr>');
        } else {
            $('[id$=tblAssigned]').find('.empty').remove();
        }

        if ($('[id$=gvCompanyListing] td').closest('tr').length == 0) {
            //var colspan = $('[id$=gvCompanyListing] th').length;
            //$('[id$=gvCompanyListing]').append('<tr class="empty"><td colspan=' + colspan + '>No records were found</td></tr>');
        } else {
            $('[id$=gvCompanyListing]').find('.empty').remove();
        }
    }

<asp:GridView ID="gvCompanyListing" runat="server" AutoGenerateColumns="False" ShowHeader="False" GridLines="None" >
                        <Columns>
                            <asp:TemplateField>
                                <ItemTemplate>
                                    <asp:CheckBox ID="cbSelect" CssClass="gridCB" runat="server" ItemStyle-Width="10%"></asp:CheckBox>
                                </ItemTemplate>
                            </asp:TemplateField>
                            <asp:BoundField DataField="client_name" SortExpression="CompanyInfo" ItemStyle-Width="92%" ItemStyle-Height="1px" ControlStyle-CssClass="companyInfo"></asp:BoundField>
                        </Columns>
                    </asp:GridView>
                <table id="tblAssigned" runat="server">
                    </table>

 protected void btnRequestAccess_Click(object sender, EventArgs e)
          {

        try
          {
            System.Text.StringBuilder strBuild = new System.Text.StringBuilder();
            string strUserName = Session["UserName"].ToString();
            int nUserName = strUserName.Length;
            int nRemaing = nUserName - 21;
            //string strActualName = strUserName.Substring(21, nRemaing);
            strBuild.Append("Request to set Clients to Hays user " + strUserName + "\n");
            int nval = 0;


            for (int i = 0; i <= this.tblAssigned.Rows.Count; i++)
            {

                  HtmlTable td = (HtmlTable)tblAssigned.FindControl("companyInfo");

                if (td != null)
                {
                    strBuild.Append(tblAssigned.Items[i].Text.ToString()+"\n")
                    nval = nval + 1;
                }
            }
          }
}