Where can I find the APO tables with thier descriptions?

Where I can browse the overall relevant tables for APO DP, SNP, PPDS and GATP?

Is there any document which contains listing and/or relationship between SAP APO tables?

Though this question seem to be quiet open ended.

I guess you knew that in APO, apart from APO tables.. it is Livecache where the actual transaction data is stored. 

But, if you just want to find some of the existing table in APO.. simply go to se11 and in the table name put the pattern as /SAPAPO/* and press F4. It will give a list of tables with the descriptions. 

You can find out yourself all APO tables application wise with the following steps:

Use transaction SE11 or SE16
- Press F4 in the selection field 
- You will get popup... in the below line of the popup selection SAP Applications.

Here you will get the Application list.  In that select your own application for which you want to get the table details
e.g. SCM- Supply Chain Management --> SCM-APO --> Advanced Planning and Optimization --->SCM-APO-MD - Master Data --> /SAPAPO/00_PRODUCT 

Here are some examples:
/SAPAPO/v_matloc - material, material number location view
/SAPAPO/TSAREAKO - Planning Area details
/SAPAPO/TSAREATE - Planning Area technial fields

Since there are thousands of tables, I cannot list them all here. 

or

You can use transaction ST05 (database trace) to help you find the tables you are looking for. You can turn on the trace function, run an APO transaction, and looks at the ST05 logs for the tables :)

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