for image display remove Server.MapPath use only following code ..if image are present in ur website folder
img.ImageUrl ="~/Teacher/" + ExcelTable.Rows[i][7].ToString();
for new row simply add br tag next to label text..exampal
Label name = new Label();
name.ID = "name" + i;
name.Text = ExcelTable.Rows[i][1].ToString()+"</br>";
or u may add every time new label with text as br...for example
Label MyNewLine = new Label();
MyNewLine.Text = "<br/>";
hope it will help