If a Member(struct) has 10 fields, the contract stores an array of Members, how would I pass 100 Members worth of data into the contract?
It's not recommended to keep a lot of data on the blockchain, rather you can use some storage solutions like IPFS or Swarm. By this, you can store the data on one of them and the hash of the files/attributes can be stored on the smart contract.
So basically using IPFS/Swarm is a smarter way of storage, you can store the data on blockchain as well, but in that case storing data would cost you more gas in comparison to storing the hash(pointing to your data).
Blockchain and IPFS/Swarm can be a really good combination, as it becomes more secure because your data is not on blockchain network.