Taifun's suggestion may work for you
http://puravidaapps.com/table.php(edit: link updated to App Inventor 2 version of the example)
alternatively, you can use a Canvas with a grill of lines and place text in it as you proposed
or you can make a very nice schedule, just using a single label and using the control character " \n " to change line position (using it in a text string is like a carriage-return).
No lines, but it is formatted.
For instance:
This is my lesson for Friday \n this is my lesson for Monday \n this is my lesson for Tuesday will display the following in a label:
This is my lesson for Friday
this is my lesson for Monday
this is my lesson for Tuesday
if you put two /n/n you get
This is my lesson for Friday
this is my lesson for Monday
this is my lesson for Tuesday
Regards,
Steve