HtmlTableCell tblCell = new HtmlTableCell();
Panel pnlA= new Panel(); Panel pnlB= new Panel();
Label lblA = new Label();Label lblB = new Label();

lblA.Style.Add("font-size", "10px");
lblA.Text = "Content A";
pnlA.Controls.Add(lblA);

lblB.Style.Add("font-size", "10px");
lblB.Text = "Content B";
lblB.Style.Add(HtmlTextWriterStyle.TextAlign, "center");
pnlB.Controls.Add(lblB);

tblCell.Controls.AddAt(0, pnlA);
tblCell.Controls.AddAt(1, pnlB);