A family of Microsoft relational database management systems designed for ease of use.
I first encountered this problem many years ago in Access 95. Firstly, you should never enter data in a table's raw datasheet, only via a form. This is true regardless of this issue. When designing the form do not drag the field from the field list to the form, but add a text box control to the form and set its ControlSource property to the name of the field. Change the text box's EnterKeyBehavior property to 'Next line in field'. This has always worked for me.
If you've used the form wizard to create the form, delete the control from the form and add a new one as above.
Do the same in any report which returns the field.