Teradata sync tables are created by DataStage Teradata stages. Teradata Enterprise creates with a name terasync that is shared by all Teradata Enterprise jobs that are loading into the same database. The name of the sync table created by the Teradata Connector is supplied by the user, and that table can either be shared by other Teradata Connector jobs (with each job using a unique Sync ID key into that table) or each Teradata Connector job can have its own sync table.
These sync tables are a necessity due to requirements imposed by Teradata's parallel bulk load and export interfaces. These interfaces require a certain amount of synchronization at the start and end of a load or export and at every checkpoint in between. The interface requires a sequence of method calls to be done in lock step. After each player process has called the first method in the sequence, they cannot proceed to call the next method until all player processes have finished calling the first method. So the sync table is used as a means of communication between the player processes.
In Teradata Enterprise, you cannot avoid using the terasync table. In the Teradata Connector, you can avoid using the sync table by setting the Parallel synchronization property to No, however that stage will be forced to run sequentially in that case.