That’s normal and expected since they both use the same browser. Difference is when you have multiple apps open. All Tauri apps, along with your browser use the same libraries and binaries loaded into the memory. Meanwhile every electron app loads another browser into the memory.
Ofc I’m simplyfying a bit since if you use Firefox as your browser and Tauri uses Chromium that’s two browsers worth of memory usage, but still not 5 or 10.