You can generally use Blackjack strategy charts while playing at a casino table, as they are considered reference tools to help you make statistically optimal decisions based on your hand and the dealer’s upcard. Most casinos don’t explicitly prohibit the use of these charts, but it's important to be discreet. While the charts themselves are typically acceptable, using them in a way that draws too much attention or slows down the game could attract scrutiny, especially if it disrupts the flow or causes frustration for the dealer or other players. It's also crucial to avoid using any electronic devices, such as phones or tablets, to consult a strategy chart, as this is usually prohibited in most casinos. In general, as long as you use a chart without causing delays or drawing attention, it should be fine, but it's always wise to familiarize yourself with the casino’s specific rules to ensure you’re in compliance.