Try this sample code to create an HTML table from Datatable, modify it as per your need.
DataTable dt = new DataTable();
dt.Columns.Add("ID");
dt.Columns.Add("Name");
dt.Columns.Add("Address");
dt.Rows.Add(1, "karthik", "bangalore");
dt.Rows.Add(2, "sehwag", "delhi");
dt.Rows.Add(3, "kavya", "coimbatore");
string html = "<table><thead ><tr>";
foreach (DataColumn column in dt.Columns)
html += "<td>" + column.ColumnName + "</td>";
html += "</tr></thead><tbody>";
foreach (DataRow row in dt.Rows)
{
html += "<tr>";
foreach (DataColumn col in dt.Columns)
html += "<td>" + row[col] + "</td>";
html += "</tr>";
}
html += "</tbody></table>";
lbl.Text = html;