8 tablespoons of butter is 3.8 oz (108 g) in weight and 8 tbsp (118 mL) in volume. It is about the size of a tennis ball.

In kitchen measures
8 tablespoons
24 tsp · 8 tbsp · 0.5 cups
about the size of a tennis ball
Butter typically ranges 0.9–0.92 g/mL depending on how it's packed. A firmly packed scoop weighs more.