For crust; combine flour, sugar and pecans. Cut in butter or margarine until mixture is crumbly. Pat onto the bottom and part way up the sides of a 9 ½ inch removable bottom tart pan. Bake in a preheated 325°F or 162°C oven for 15 minutes, until browned. Remove from oven and cool.
For filling; cream sugar, milk and cream cheese until smooth. Spread onto the cooled crust.
For topping: mix sugar and cornstarch in a saucepan. Add water slowly, stirring to keep mixture smooth. Add 1 cup mashed blueberries and bring to a boil over medium-high heat. Reduce heat to medium and simmer, stirring constantly until thick, 1 to 2 minutes. Cool to warm.
Arrange the remaining blueberries on top of cream cheese layer in crust. Spoon thickened glaze over berries refrigerate at least 1 hour, preferably 3 hours. Remove tart from pan by lifting it out, keeping it on the removable bottom