A question about Ledger Nano S:
Can I keep in one device (hardware wallet) several Bitcoin wallets?
Yes... you can add multiple "accounts" within Bitcoin. Each account creates separate and unique addresses from the others and you can label them (and use different colours) to differentiate the accounts from one another.
The balance of each account is separate from the other accounts, and you cannot combine coins from separate accounts into one transaction.
As mentioned previously, you can also use different passphrases to generate completely different wallets, which are also separate from each other, but you can't "see" them together at the same time within the ledger bitcoin wallet chrome app.