C# code read an excel content from blob

public DataSet GetExcelBlobData(string filename, string connectionString, string containerName)
        {
            // Retrieve storage account from connection string.
            CloudStorageAccount storageAccount = CloudStorageAccount.Parse(connectionString);

            // Create the blob client.
            CloudBlobClient blobClient = storageAccount.CreateCloudBlobClient();

            // Retrieve reference to a previously created container.
            CloudBlobContainer container = blobClient.GetContainerReference(containerName);

            // Retrieve reference to a blob named "myblob.csv"
            CloudBlockBlob blockBlob2 = container.GetBlockBlobReference(filename);

            DataSet ds;
            using (var memoryStream = new MemoryStream())
            {
                blockBlob2.DownloadToStream(memoryStream);
                /*
                 
                    used third party open source Excel Data Reader - Read Excel files in .NET(http://exceldatareader.codeplex.com/)
                    Nuget: Install-Package ExcelDataReader (https://www.nuget.org/packages/ExcelDataReader/)
                 
                */

                var excelReader = ExcelReaderFactory.CreateOpenXmlReader(memoryStream);
                ds = excelReader.AsDataSet();               
                excelReader.Close();               
            }

            return ds;
        }