deep learning output data in keras fit method
If you are talking about time-series analysis, your test data should be the three columns you want to predict, but shifted by some amount. So the first batch (e.g. first 5 rows) predicts the 6th row. Here is a small diagram showing what I mean:

Notice that the timestamp column not in the target, and that we predict the three features in the following row, given an input of 5 rows.