Having many rows in a TableView doesn't have as much impact on the performance as having many columns instead when using JavaFX.
I tried creating around 500 columns which creates a noticeable delay (when resizing the columns for example) but only if there's an item in the TableView which creates a row. If the TableView has no items (and thereby no rows) the performance losses are not that noticeable. Also having many rows (and just a few columns) does not create any delay (I tested this with 700 rows, having no delay at all).
So what is the reason TableView lacks performance in that specific case and is there a solution this issue?