The only option to reduce the translator cache size is to reduce the translator_cache_size parameter (which defines the number of translation tables, not the maximum memory size). This parameter is exclusive for Pool/JoinEvaluator/TranslationTables. The size of other areas like Pool/JoinEvaluator/JERequestedAttributes/Results is linked to the actual (intermediate) results of database requests, so there is no way to adjusting it with central parameters.