This paper proposes a visual programming language, called VisualTPL, to perform data transformation in report generation. In VisualTPL, data transformation is accomplished by writing graphical dataflow programs, which manipulate tables as first-class objects with a set of table operations. Based on VisualTPL, a visual programming environment, called VisualTPS, has been developed. As demonstrated with an example, data transformation programming is easy and intuitive in VisualTPS. Tables with sophisticated layouts can be created through top-down decomposition and incremental development.