Compare 2 table and remove matching row in source Datatable

I used this code in assign activity

i getting error as

Please help!!!

@RachelN Can you Please Explain the Process what you are trying to do :
You can Explain your process by providing these 3 Step Information :

  1. What is the Input Data?
  2. What Operations you want to perform ?
  3. The Output Data you Expect.

Screenshots / Excel Files would be Appreciated.

It might be a Lot easier to understand the code in the Image if you paste the Code here, instead of the Screenshot :sweat_smile: