Most eSIM-capable phones can store several eSIM profiles, with typically one or two active at a time (both limits vary by model).
How to use them:
- Install eSIMs for several countries in advance and switch the active line as you travel
- Switch via iPhone "Settings → Cellular → select the line → Turn On This Line", or Android "Settings → Network & internet → SIMs"
- After switching, also set Mobile Data to the eSIM you want to use
Note: if you delete an eSIM you're done with, remember it cannot be reinstalled. If data remains, it's safer to just turn it off.