The default for nltList is to allow overflow at the cell boundary. You can use nltSpread to allow wrapping within cell, or clip selected columns at the cell boundary:

nltClip 0 1 0 0 0  © Clip 2nd column only

The available options are:

0=default (spill in List, wrap in Spread)
1=clip at cell boundary (implemented in Spread as well as List from release 1.6)
2=spill into next column always (over-ride Spread default)
3=wrap text and extend cell vertically (=Spread default, not used in List)

Clipping adds significant processing time to report production, so only use it when you need to.