If the old tablet is Android, Fotoo is perfect. Yes it costs, but one off fee and worth it. Can pull from so many different sources.
Personally, I still use Google Photos. Both my wife and I have us, the kids and pets all autotagged into an album for all the pictures taken on our phones and Fotoo randomly shows these on the Nexus 7 tablet I have taped into a wooden frame.
Or perhaps, the pro version for free, due to the sub we’re in? Mobilism