1- If the structure is equal or almost equal to the structure of your entity, you will just need to assign the structure to the entity action create/createOrUpdate.
2- If you have a list, you will just need to loop/for each the list and use the entity action create/createOrUpdate to create each record from the list.
I recommend to see some guided path or training course on reactive to learn this.
With a structure that is not a list you will not put anything on a table just in some cases where is related to a record in a list.
With a list you just need to aggregate the data of that entity and use the output from the list to show the data. You can use scaffolding to crate everything you want, by dragging and drop the entity in flow or screen.
Kind Regards,
Márcio