source: addons/HeuristicLab.MetaOptimization/HeuristicLab.MetaOptimization.Test/TableBuilder.cs

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

namespace HeuristicLab.MetaOptimization.Test {
  public class TableBuilder {
    private List<string> columnNames;
    private List<string[]> rows = new List<string[]>();

    public TableBuilder(params string[] columnNames) {
      this.columnNames = new List<string>(columnNames);
      AppendRow(columnNames);
    }

    public void AppendRow(params string[] values) {
      if (values.Length != columnNames.Count)
        throw new ArgumentException("Value count does not match column name count");
      this.rows.Add(values);
    }

    public override string ToString() {
      StringBuilder sb = new StringBuilder();
      int[] columnSizes = GetColumnSizes();

      for (int rowIdx = 0; rowIdx < rows.Count; rowIdx++) {
        if (rowIdx == 1) {
          sb.AppendLine(string.Join("", Enumerable.Repeat("-", columnSizes.Sum() + columnSizes.Count())));
        }
        for (int colIdx = 0; colIdx < rows[rowIdx].Length; colIdx++) {
          sb.AppendFormat("{0} ", rows[rowIdx][colIdx].PadLeft(columnSizes[colIdx]));          
        }
        sb.AppendLine();
      }
      return sb.ToString();
    }

    private int[] GetColumnSizes() {
      int[] sizes = new int[columnNames.Count];
      for (int i = 0; i < columnNames.Count; i++) {
        foreach (var row in rows) {
          if (row[i].Length > sizes[i])
            sizes[i] = row[i].Length;
        }
      }
      return sizes;
    }
  }
}