Best /Fastest way to read an Excel Sheet into a DataTable?

If you want to do the same thing in C# based on Ciarán Answer

string sSheetName = null;
string sConnection = null;
DataTable dtTablesList = default(DataTable);
OleDbCommand oleExcelCommand = default(OleDbCommand);
OleDbDataReader oleExcelReader = default(OleDbDataReader);
OleDbConnection oleExcelConnection = default(OleDbConnection);

sConnection = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\Test.xls;Extended Properties=\"Excel 12.0;HDR=No;IMEX=1\"";

oleExcelConnection = new OleDbConnection(sConnection);
oleExcelConnection.Open();

dtTablesList = oleExcelConnection.GetSchema("Tables");

if (dtTablesList.Rows.Count > 0) 
{
    sSheetName = dtTablesList.Rows[0]["TABLE_NAME"].ToString();
}

dtTablesList.Clear();
dtTablesList.Dispose();


if (!string.IsNullOrEmpty(sSheetName)) {
    oleExcelCommand = oleExcelConnection.CreateCommand();
    oleExcelCommand.CommandText = "Select * From [" + sSheetName + "]";
    oleExcelCommand.CommandType = CommandType.Text;
    oleExcelReader = oleExcelCommand.ExecuteReader();
    nOutputRow = 0;

    while (oleExcelReader.Read())
    {
    }
    oleExcelReader.Close();
}
oleExcelConnection.Close();

here is another way read Excel into a DataTable without using OLEDB
very quick
Keep in mind that the file ext would have to be .CSV for this to work properly

private static DataTable GetDataTabletFromCSVFile(string csv_file_path)
{
    csvData = new DataTable(defaultTableName);
    try
    {
        using (TextFieldParser csvReader = new TextFieldParser(csv_file_path))
        {
            csvReader.SetDelimiters(new string[]
            {
                tableDelim 
            });
            csvReader.HasFieldsEnclosedInQuotes = true;
            string[] colFields = csvReader.ReadFields();
            foreach (string column in colFields)
            {
                DataColumn datecolumn = new DataColumn(column);
                datecolumn.AllowDBNull = true;
                csvData.Columns.Add(datecolumn);
            }

            while (!csvReader.EndOfData)
            {
                string[] fieldData = csvReader.ReadFields();
                //Making empty value as null
                for (int i = 0; i < fieldData.Length; i++)
                {
                    if (fieldData[i] == string.Empty)
                    {
                        fieldData[i] = string.Empty; //fieldData[i] = null
                    }
                    //Skip rows that have any csv header information or blank rows in them
                    if (fieldData[0].Contains("Disclaimer") || string.IsNullOrEmpty(fieldData[0]))
                    {
                        continue;
                    }
                }
                csvData.Rows.Add(fieldData);
            }
        }
    }
    catch (Exception ex)
    {
    }
    return csvData;
}