As of MDL-32112, table names are limited to 28 characters. Some of the table names in the ILP block exceed this, making it impossible to install on Moodle 2.3.
Until the problem is fixed, you can work around it by changing the limit in lib/xmldb/xmldb_table.php. The Constant NAME_MAX_LENGTH is defined at the top of the file. Be careful if you do this though - according to the comments in the file, Oracle has a hard limit of 30 characters.