client: send or receive bitcoins with bitcoin-cli without downloading complete blockchain

I have successfully downloaded, compiled and installed bitcoin-cli from github.

I can send or receive bitcoins with sendtoaddress and getnewaddress methods.

It works very well and I am happy to do it without installing third-party software (I don't trust them)

But I have a problem: I need to download the complete blockchain files (with bitcoind) on my computer.

Is there any way to run sendtoaddress and getnewaddress just by having the wallet.dat file on my computer? I don't want to download the complete blockchain files. It's possible ?

How does the ledger wallet key work? This small key does not contain a copy of the blockchain. And works !

Thank you