One question about Pricing and Conditions puzzle me for a long time!

One question about Pricing and Conditions puzzle me for a long time.I take one example to explain my question:

1-First,my sale order use pricing procedure RVAA01.

2-Next,the pricing procedure RVAA01 have some condition type,such as EK01(Actual Costs),PR00(Price)....,and so on.

3-Next,the condition type PR00 define the Access Sequences PR00 as it's Access Sequences.

4-Next,the Access Sequences PR00 have some Condition tables,such as:

table 118 : "Empties" Prices (Material-Dependent)

table 5 : Customer/Material

table 6 : Price List Type/Currency/Material

table 4 : Material

5-Next,I need to maintain Condition tables's Records.Such as the table 5(Customer/Material).I guess the sap would supply one screen for me to input the data of table 5.At this screen,the sap would ask me to select one table,such as table 5.When I select the table 5,the sap would go to the screen to let me input the data of table 5.But when I use the T-CODE VK31 or VK32 to maintain Condition tables's Record,I found it's total different from my guess:

A-First,I can not found one place for me to open the table,such as table 5,to let me input the data?

B-Second,For example,when I select the VK31->Discounts/Surcharges->By Customer/Material,the sap show the grid view at the right side.At the each line of the grid view,you need to select the Condition Type at the first field.And this make me confused very much.Why the sap need me to select one Condition Type but not the Condition table?To the normal logic,it ought not to select Condition table but not the Condition Type!

Dear all,I'm a new one in sd.May be this is a very stupid question.But it did puzzle me for a long time.If any one can explain this question in detail and let me understand the concept,I will appreciate him/her very much.Thank you.