Hypothetically, a single tarantula bite is not lethal to humans. Tarantulas have venom, but their venom is typically not potent enough to cause significant harm to healthy adults. In general, tarantula bites can cause localized pain, swelling, and irritation, similar to a bee sting, but they are not life-threatening.
If we consider a scenario where a substantial number of tarantulas were to bite a human simultaneously, the outcome would still depend on various factors, including the individual's health, possible allergic reactions, and the effectiveness of their immune system. However, it is highly unlikely, if not impossible, for a group of tarantulas to collectively deliver enough venom to kill a healthy human.
In summary, while it's an interesting hypothetical scenario, in reality, tarantulas do not pose a lethal threat to humans under normal circumstances.