You should check the Borland vcl documentation - isn't TEdit a single-line edit control wrapper anyway? If that's the case you'll probably have to use another control that supports multiline - TMemo, maybe?
This is all guesswork as it's been a long time since I last fiddled around with borland builder. In the absence of someone more informed about bcb, check the documentation and look for a method/flag for the control(s) of interest that may enable multiline behaviour.
