test.cs

// attach events to monitor available merge fields and merge blocks
dsManager.PossibleMergeFieldColumnsChanged += 
    DsManager_PossibleMergeFieldColumnsChanged;
dsManager.PossibleMergeBlockTablesChanged += 
    DsManager_PossibleMergeBlockTablesChanged;

// attach the available tables to the combobox
cbMasterTable.DataSource = 
    dsManager.DataTables.ToList<DataTableInfo>();
cbMasterTable.DisplayMember = "TableName";