Krishna
It is a dashboard where one column will be updated by user which ultimately will be saved in custom table. User can put filter on UI side to apply same value to all selected line items.
I could not find any benchmark in SAP documentation which states that you can only process < N number of entries through gateway. If you closely look at link shared by Ekansh it has documented testing with max of 2500 products and runtime piece seems to be pretty fast.
I am not sure about used case for leveraging REST API in ABAP. If you can share some links i will like it check that out too.
Here is document which i found for REST API which states ...
"For productive business scenarios SAP recommends to use the SAP NetWeaver Gateway which provides all qualities for REST services based on the OData standard."
Message was edited by: Anil Kumar Raina