CASTING from raw data to custom table giving junk values

I have a report where we are reading the log value using FM 'DBLOG_READ_TABLE'

We are reading the values in field symbol for the custom table.

but the casting from raw data to custom table(eg:zemployee) is giving junk values here.

DATA:  ls_log_list TYPE dbtablog,

       lt_log_list TYPE stprt_log_stable_type.

FIELD-SYMBOLS: <lf_content> TYPE any.

    CALL FUNCTION 'DBLOG_READ_TABLE'

      EXPORTING

        from_day  = l_beg_date

        from_time = l_beg_time

        to_day    = l_end_date

        to_time   = l_end_time

        obj_list  = lt_obj_list

        user_list = lt_user

      CHANGING

        log_list  = lt_log_list.

ASSIGN ls_log_list-logdata TO <lf_content>

CASTING TYPE (ls_log_list-tabname).

Here ls_log_list-tabname is having name of custom table.For eg:zemployee.