Two tables are possible for trailers:
This table shows working intervals if the chosen trailer if it was bound
 to units. It comes along with information on fuel consumed, distance 
traveled etc. Parameters and possible columns for this table are the 
same as in the similar table for drivers (with the exception that the column 'Violations' is absent). The Bindings table can be also generated for trailer groups — it gives possibility to build complicated four-level reports 
(trailers –> units –> dates/weeks/months –> single bindings). More...
This table represents the list of custom fields created in trailer properties. It is not available for trailer groups.