Not true for Edge, which is only two configuration slots + U2F. The NEO, NEO-n, 4, and 4 Nano all have the OATH applet though. These four YubiKey models can store approximately 30 OATH-TOTP or OATH-HOTP credentials, independent of the two configuration slots. With the NEO, obviously you can use the Yubico Authenticator app on Android to store/view these credentials. On a computer, you will need to make sure that CCID is enabled before attempting to add the credentials with Yubico Authenticator. If you have used the Yubico Authenticator app for a different device previously, you may need to check the settings and confirm that "read from slot 1" and "read from slot 2" are not enabled, as this will prevent you from storing new credentials on the OATH applet.
This is BRIEFLY covered here -
https://developers.yubico.com/yubioath-desktop/