You can cut off the flowering stem below where no more hands are forming. The size of your fruits will be substantially determined by the variety of your banana. However, the size and number of fruits are determined over the course of a full year of growth . If you skimped, you may get 20-25 fruits. Feed well for best appearance, maximum fruit numbers and taste and quality.
Home grown bananas are excellent for flavor.
Home grown bananas far exceed grocery store varieties for taste . There is a freshness and a sweetness and a tang unmatched by grocery store fruit. As your banana fingers get fatter and fatter, at some point they stop getting bigger. Observe your fruit often to notice this growth and the stoppage of growth. About 4-6 weeks after finger growth has stopped, cut off the whole stalk of bananas .