Consolidator is a Business that sells airline tickets in bulk, usually at some savings, but with many restrictions - be careful who you use !
Other definition:
Consolidator is a company that buys blocks of seats from airlines and sells them through travel agents, usually at a discount.
Other definition:
Consolidator is a person or company which forms groups to travel on air charters or at group fares on scheduled flights to increase sales, earn override commissions or reduce the possibility of tour cancellations.