Thanks to VCheim's suggestion I was able to acheive my goal. Where is what I did: Create the main reportConnect the main report to the data adapter you want to use to fill the table. In my case, it's a csv data file. Choose csv as the language, and click "read fields" to get the fields created automatically. Now your main report has access to all these fields.Drag a table into the detail band. Choosing new dataset is fine at this point and clicking finish. This will just create a name for the table's dataset but not set any values.At the moment there are two datasets. The main report's, which doesn't have a name, and the table's, which by default is called Dataset1. Now, we need to "send" the dataset of the main report to the table, by following the suggestion, that is: From the main report, click the table and select the Dataset tab.Select JRDatasource expression, and enter this expression: $P{REPORT_DATA_SOURCE}The final step is to make sure your Dataset1 has the same field names and types as your main report's. (From some experimenting I found that it doesn't matter what dataadapter you set to Dataset1 or what language - none of this is taken into account once we tell the table to read the report's data source.)All set to go now, just drag your fields into the detail row of the table, click preview to see that the table is showing the data.
