The reserve factor is the percentage of Fee paid to Metalend protocol. If the reserve factor is 10, then that would imply that 10% of the interest paid on the asset is for Metalend.
On the other hand, the collateral factor is the maximum you can borrow on a particular asset.
Example: The collateral factor for ETH is 82%, if the price of ETH is considered as $1000, the max you will be able to borrow in other assets is worth $820