single dataset we using two table report.here column is Name in dataset but two table saparete name

HI My data set one column name is FULLNAME

but i have two table in visulazation(reports)

1st table column is FULLNAME

2nd table column is EMPLOYEE but samedataset.

i drag and drop FULLNAME column in 2nd table but i need replace EMPLOYEE is column name

how edit name in report

suppose i can add new columns(FULLNAME=EMPLOYEENAME)  its work fine.

but exxtra column added accupy extra memory

if possible chnage column name is report like SSRS

thanks

Aruna