Yes, you can connect several API accounts in your cabinet. However if multiple API accounts are linked to a single Binance account, that can create a conflict. For example, if you are an investor and have 2 APIs from the single Binance account and you connected these APIs to 2 different traders then they can have a conflicting strategy. Trader number one will buy BTC/USDT and the second can cancel that deal by doing the opposite trade of selling BTC/USDT.