Hi,
Please user the Validation Group property for that.
For Example, 1st table control has validation group 'address' and that submit button has also validation group 'address' then when you click on button at that that time it will validate those controls whole validation group is 'address'.
For the second table controls you can user another validation group like 'Details'.
see the example in the below link. It might be help you and you will get the idea.
http://www.w3schools.com/aspnet/prop_webcontrol_button_validationgroup.asp[
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Thanks,
Viprat