When you are creating an ETS table without a registered name (check the option named_table) the table is created with a reference. No matter how many you create, the old ones are still there so, yes, you have a leak of memory if you are not deleting the old ones.
One way to avoid this is by using the named_table option. This is crashing if the previous table exists. You can put the creation of the table with a catch or inside a try-catch block.
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