1. A memory device comprising: a nonvolatile memory; a volatile memory; and a controller which writes a first data table including a first data group comprising a first conversion table including a first logical address corresponding to a first physical address set in a first area of the nonvolatile memory and a first count value as the number of read requests for the first logical address and a second data group comprising a second conversion table including a second logical address corresponding to a second physical address set in a second area of the nonvolatile memory and a second count value as the number of read requests for the second logical address, to the volatile memory, reads the first data table when a third logical address corresponding to a third physical address set in a third area of the nonvolatile memory is requested to be read, compares the first count value and the second count value with each other if the third logical address is not detected in the first data table, and rewrites the first data group or the second data group of the first data table to a third data group comprising a third conversion table including a third logical address and a third count value as the number of read requests for the third logical address based on a result of the comparison.