Why is my keyboard tiny?

Perhaps you have enabled the iPad's floating keyboard...

The installed version of iPadOS (not mentioned) will determine how you restore the full on-screen keyboard.

If you have installed iPad iPadOS 26/27, touch the small three-dot button at the bottom of the small floating keyboard to expose a menu. From the menu, select the full keyboard:

For earlier versions of iPadOS, to restore the Floating Keyboard to the normal on-screen keyboard presentation, use the two-finger “zoom” gesture (i.e., the reverse of the two-finger “pinch”).

If the Split Keyboard is restored instead of the full on-screen keyboard, you can either use two fingers (one on each of the two half-keyboards) and swipe the two halves together - or touch-and-hold the “keyboard” key, then slide your finger to the Merge & Dock option and release.

Use the floating keyboard on your iPad – Apple Support

Split and move the keyboard on your iPad – Apple Support