As per the standard global GeoPackage specification, the name of a GeoPackage table created by MapInfo Pro is in lower case. For reference, see www.geopackage.org/spec/#_base.
GeoPackage files created by other software may not always follow this specification. If you are using the Register Table statement in MapBasic to open a GeoPackage table created by another product, you will need to pass the table name in the correct case. Otherwise, MapInfo Pro returns an error.