Hi @AZ_Shashank Sharma ,
Could you please elaborate more on below ask?
"how to do the mapping of Guid of table A as foreign key parameter to Table B"
However, in second copy activity source tab you can utilize addition column feature and pass your GUID value as new column there.
Please Note, Copy activity in Azure data factory is purely meant for Data movement. Data flows in ADF helps to perform data transformations and then load data in to target.