test.cs

using TXTextControl;
using TXTextControl.DocumentServer;
using TXTextControl.DocumentServer.DataSources;

using (ServerTextControl tx = new ServerTextControl())
{
    tx.Create();

    string jsonData = File.ReadAllText("tabledata.json");

    DataSourceManager dataSourceManager = new DataSourceManager();
    dataSourceManager.LoadJson(jsonData);

    MergeBlockInfo mergeBlockInfo = new MergeBlockInfo("items");
    mergeBlockInfo.ColumnNames.Add("product");
    mergeBlockInfo.ColumnNames.Add("price");
    mergeBlockInfo.ColumnNames.Add("quantity");

    MergeBlockSettings mergeBlockSettings = new MergeBlockSettings(BlockTemplateType.TableRow, true);

    dataSourceManager.InsertMergeBlock(tx, mergeBlockInfo, mergeBlockSettings);

    MailMerge mailMerge = new MailMerge()
    {
        TextComponent = tx
    };

    mailMerge.MergeJsonData(jsonData);

    // save the document as PDF
    tx.Save("results.pdf", StreamType.AdobePDF);
}