How to retrieve a list of tables which are in my SAP system with ABAP program?

I need to retrieve a list of tables which are in my SAP system, can someone explain how to make this? I am new with ABAP. I have to write a program for this with input field for table name and value search.

Thank you.

You can query the following SAP tables to get the data:

• DD02L SAP Tables: information about the tables
  
• DD02T SAP Table Texts: table descriptions

By selecting the data from DD02L you can put additional conditions to retrieve the tables you need. Most probably you may want to restrict the query to get:

• only custom tables:
  ( tabname LIKE 'Z%' OR tabname LIKE 'Y%' )
  
• only activated tables, i. e. entries activated or generated in this form:
  as4local = 'A'
• only database tables TRANSP and / or structures INTTAB:
  tabclass IN ('TRANSP', 'INTTAB')

So you can start with the query:

  SELECT * FROM dd02l INTO TABLE @DATA(lt_tables)
     WHERE ( tabname LIKE 'Z%' OR tabname LIKE 'Y%' )
       AND as4local = 'A'
       AND tabclass IN ('TRANSP', 'INTTAB').

and develop it further as you need according to your requirements.