Creating number and strings values is pretty efficient in Lua, Numbers do not have any additional data structure associated with them and are freed immediately when no longer used. Strings are hashed and stacked together with same strings, so creating 10000 copies of "Hello, world!" or creating and freeing it repeatedly will not produce garbage. Tables, however, always take memory when created that always becomes garbage when table is no longer used. If you do not want to create unnecessary garbage either avoid using tables unless it is really necessary or, in case several of your throw-away tables use same set of fields, or each new calculation uses superset of field of previous table, use only one table instead of creating new table for every calculation. For example, if you need to sort