// Define attributes to get and keys to retrieve
List<string> attributesToGet = new List<string> { "Author", "Title", "Year" };
List<Dictionary<string, AttributeValue>> sampleTableKeys = new List<Dictionary<string, AttributeValue>>
{
    new Dictionary<string, AttributeValue>
    {
        { "Author", new AttributeValue { S = "Mark Twain" } },
        { "Title", new AttributeValue { S = "The Adventures of Tom Sawyer" } }
    },
    new Dictionary<string, AttributeValue>
    {
        { "Author", new AttributeValue { S = "Mark Twain" } },
        { "Title", new AttributeValue { S = "Adventures of Huckleberry Finn" } }
    }
};

// Construct get-request for first table
KeysAndAttributes sampleTableItems = new KeysAndAttributes
{
    AttributesToGet = attributesToGet,
    Keys = sampleTableKeys
};

// Define keys to retrieve
List<Dictionary<string, AttributeValue>> authorsTableKeys = new List<Dictionary<string, AttributeValue>>
{
    new Dictionary<string, AttributeValue>
    {
        { "Author", new AttributeValue { S = "Mark Twain" } },
    },
    new Dictionary<string, AttributeValue>
    {
        { "Author", new AttributeValue { S = "Booker Taliaferro Washington" } },
    }
};

// Construct get-request for second table
//  Skip setting AttributesToGet property to retrieve all attributes
KeysAndAttributes authorsTableItems = new KeysAndAttributes
{
    Keys = authorsTableKeys,
};

// Create a client
AmazonDynamoDBClient client = new AmazonDynamoDBClient();

// Construct table-keys mapping
Dictionary<string, KeysAndAttributes> requestItems = new Dictionary<string, KeysAndAttributes>();
requestItems["SampleTable"] = sampleTableItems;
requestItems["AuthorsTable"] = authorsTableItems;

// Construct request
BatchGetItemRequest request = new BatchGetItemRequest
{
    RequestItems = requestItems
};

BatchGetItemResult result;
do
{
    // Issue request and retrieve items
    result = client.BatchGetItem(request).BatchGetItemResult;

    // Iterate through responses
    Dictionary<string, List<Dictionary<string, AttributeValue>>> responses = result.Responses;
    foreach (string tableName in responses.Keys)
    {
        // Get items for each table
        List<Dictionary<string, AttributeValue>> tableItems = responses[tableName];

        // View items
        foreach (Dictionary<string, AttributeValue> item in tableItems)
        {
            Console.WriteLine("Item:");
            foreach (var keyValuePair in item)
            {
                Console.WriteLine("{0} : S={1}, N={2}, SS=[{3}], NS=[{4}]",
                    keyValuePair.Key,
                    keyValuePair.Value.S,
                    keyValuePair.Value.N,
                    string.Join(", ", keyValuePair.Value.SS ?? new List<string>()),
                    string.Join(", ", keyValuePair.Value.NS ?? new List<string>()));
            }
        }
    }

    // Some items may not have been retrieved!
    //  Set RequestItems to the result's UnprocessedKeys and reissue request
    request.RequestItems = result.UnprocessedKeys;

} while (result.UnprocessedKeys.Count > 0);