source: Common/Table.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Windows.Forms;
using System.Text;

namespace Common
{
    public enum OutputFormat
    {
        Excel,
        Plain,
        Csv,
        Html,
        ListView
    };

    public class Row
    {
        public List<string> Cells = new List<string>();

        public void AddCell(string text)
        {
            Cells.Add(text);
        }
    }

    public class Table
    {
        public List<Row> Rows = new List<Row>();

        public void Clear()
        {
            Rows.Clear();
        }

        public Row AddRow()
        {
            Row row = new Row();
            Rows.Add(row);
            return row;
        }

        public string GetOutputTabs()
        {
            StringBuilder output = new StringBuilder();
            foreach (var row in Rows)
            {
                output.AppendLine(string.Join("\t", row.Cells));
            }
            return output.ToString();
        }

        public string GetOutputPlain()
        {
            StringBuilder output = new StringBuilder();
            foreach (var row in Rows)
            {
                output.AppendLine(string.Join(Environment.NewLine, row.Cells));
                output.AppendLine();
                output.AppendLine("===========================");
                output.AppendLine();
            }
            return output.ToString();
        }

        public string GetOutputCsv()
        {
            StringBuilder output = new StringBuilder();
            foreach (var row in Rows)
            {
                output.AppendLine(string.Join(",", row.Cells.Select(x => "\"" + x + "\"")));
            }
            return output.ToString();
        }

        public string GetOutputHtml()
        {
            StringBuilder output = new StringBuilder();
            output.AppendLine("<table border=\"1\">");
            foreach (var row in Rows)
            {
                output.AppendLine("<tr><td>" + string.Join("</td><td>", row.Cells.Select(x => x.Replace(Environment.NewLine, "<br/>"))) + "</td></tr>");
            }
            output.AppendLine("</table>");
            return output.ToString();
        }

        public void GetOutputListView(ListView listView)
        {
            foreach (var row in Rows)
            {
                if (listView.Columns.Count == 0 && row.Cells.Count > 0)
                {
                    while (listView.Columns.Count < row.Cells.Count)
                        listView.Columns.Add(row.Cells[listView.Columns.Count]);
                }
                else
                {
                    while (listView.Columns.Count < row.Cells.Count)
                        listView.Columns.Add("");
                    ListViewItem item = new ListViewItem();
                    int i = 0;
                    foreach (var cell in row.Cells)
                    {
                        if (i == 0) item.Text = cell;
                          else item.SubItems.Add(cell);
                        i++;
                    }
                    listView.Items.Add(item);
                }
            }

            foreach (ColumnHeader column in listView.Columns)
            {
                column.Width = listView.Width / listView.Columns.Count;
            }
        }

        public string GetOutput(OutputFormat outputFormat)
        {
            if (outputFormat == OutputFormat.Excel) return GetOutputTabs();
            else if (outputFormat == OutputFormat.Plain) return GetOutputPlain();
            else if (outputFormat == OutputFormat.Csv) return GetOutputCsv();
            else if (outputFormat == OutputFormat.Html) return GetOutputHtml();
            else return "";
        }
    }
}