Hi @harry17 ,
Could you please share a bit more about your scenario?
Do you want to copy multiple records from one Entity to another Entity?
Based on the needs that you mentioned, I think the ForAll function and Patch function could achieve your needs. Please consider take a try with the following workaround:
Set the OnSelect property of the button in your Edit form to following:
ForAll(
'First Entity',
Patch(
'Second Entity',
Defaults('Second Entity'),
{
Column1: 'First Entity'[@Column1],
Column2: 'First Entity'[@Column2],
Column3: 'First Entity'[@Column3],
...
...
}
)
)
As an another solution, I think Power Automate could achieve your needs. You could also consider set up a Power Automate flow as below:

then trigger above flow, then these records from your Entity A would be synced to Entity B.
Please take a try with above solution, then check if the issue is solved.
Best regards,