"FEB-2010" is not a Date, so it would not make a lot of sense to store it in a date column.
You can always extract the string part you need , in your case "MON-YYYY" using the TO_CHAR logic you showed above.
If this is for a DIMENSION table in a Data warehouse environment and you want to include these as separate columns in the Dimension table (as Data attributes), you will need to store the month and Year in two different columns, with appropriate Datatypes...
Example..
Month varchar2(3) --Month code in Alpha..
Year NUMBER -- Year in number
or
Month number(2) --Month Number in Year.
Year NUMBER -- Year in number