Hi @Jean_Safar,
Welcome to the forum 
There is no limitation as per the DAML ledger model.
There are other technical limitations though. The RPC protocol used for the ledger api (gRPC) specifies a maximum message size that defaults to ~4MB. So both client and ledger need to be configured to accept messages larger than that. (See for example this post).
Additionally one has to consider that DAML contract values need to be serialized, deserialized, sent to the committer for validation, translated for the ledger api, etc, so large values definitely have an impact on performance in one way or another.
Iād be interested in what context you are using DAML? Only if you can share that with us, of course?