Welcome to Android Central! Which tablet? On most Android devices, the clipboard is a system function, not a separate app. It is very transient, and only holds the last thing you copied. To see what's in there, go to any blank text field (like on a note-taking app), long-press and tap Paste.
But some devices do have a clipboard that saves multiple items and allows you to see them, so we need to know which one you have.