You can open multiple types of accounts, but you cannot have multiple of the same type of account; the only way you can do this is if you have different account types with Lime.
For example, you cannot have two individual accounts, but you can have one individual, one IRA, one JTWROS, etc.
If you have several accounts, you can view them within your account portal under the drop-down menu on the top left corner of the screen, allowing you to switch between the accounts without having to log out.