storage space

good day!

i have the ff: table structures:

Table "quantities"
Attribute | Type | Modifier
-----------+---------------+----------
invnbr | varchar(12) |
ordernbr | varchar(12) |
prodid | varchar(30) |
invqty | numeric(12,2) |
uprice | numeric(12,2) |

Table "notes"
Attribute | Type | Modifier
-----------+---------------+----------
ordernbr | varchar(12) |
line1 | varchar(60) |
line2 | varchar(60) |
line3 | varchar(60) |

with the above structures, is it advisable to separate "notes" table from
"quantities" to save storage space because an invoice to us may or may not
have note/s?

thanks,
don