Hi Hardik,
Maintaining a z table is not a suggestible option but some time we have to do that.
If you are ok with creating a new z table then , you can use one discount condition & one routine for this condition in pricing. This routine will find out the day with the help of function module - RH_GET_DATE_DATNAME. You can maintain the day wise discount in the z table. This will also help you to easily change the discounts in future. Lets say, the discount for Monday is 10% & Tuesday it is 9 %. In future if you want to change these discounts to lets say 8% & 7% , then business can directly change it in the table with the help of new tcode with proper authorizations.
The routine will check the day from FM & relevant discount from table & put it in SO.
Thanks
Ajit.