deleting query history

hi guys,

I need to clear my query history.I wrogly select top 1000 rows from menu and this 1000 rows listed in 01.46 minutes.But,there are 11 million rows in the table and ı need to get the elapsed time.when I use the select * from "table name" ,this 1000 rows automatically listed in 0 times.Now I need to clear all the history to get elapsed time correctly.Sorry,I'm a new trainee in ms sql,If ıt is an easy question.

thanks your helps.