Have a look here:

http://www.malev.com/travelinformati...al-information

carry on:
in Business 2 bags total 18KGs (first one 10 KG and second one 8 KG)

Check-in bags:
30 KGs for Malev operated flights (since they do not fly to other fregions rather than EU-EU or EU-Middleast any more) I assume the check-in baggage is weight based. No regardless how many suitcases you take you can always take two smaller oneson board and check-in suitcases total under 30 KGs