The workflow have the limitation of the maximum allowed size for a workflow definition is 400KB. The maximum allowed size for a workflow definition plus its input is 1.5MB
Also the loop has its own limitation,
The array you select can contain no more than 100 items. If an item in this list is larger than 512KB, that item will fail when the loop is executed.
So you may use Search API and limit the results to execute in the loop. If your use case is to remove the entitlements use cert campaign and campaign filter to get all the entitlements from a specific source and avoid the loop. The information is here