Size Category & performance

Dear All,

I like to know is there any relation ship between the size category of a tables and performance when the same table is used in report.

table LTAK(Header table) is having size category 4 Data records expected 130000-10000000

table LTAP(item table) is having size category 2 Data records expected 3100 – 12000

in my case Item table contains around 2838000 records and header table contains 929000 records so because of size category my performance will be low ?

I am using SELECT * clause and "FOR ALL ENTRIES" clause

thanks & best regards

Vinayak