Cannot delete multiple recent calls or find Edit option

You need to reset one or all of these three settings, Display Zoom, Font size and/or Bold Text. Once you’ve confirmed all three settings are at their defaults, restart your device and should see the editing options.

You have done something to increase your font size. The "Edit" prompt is therefore not shown.

One brute force way to undo your large font is:

Settings > General > Transfer or Reset iPhohe > Reset > Reset All Settings