There are two BDE configuration settings that control how Blobs are handled.
BlobsToCache
Specifies how the BDE caches blobs when a dataset is traversed. If the value is set too low, this will result in an ‘Invalid Blob Handle’ error. Set BlobsToCache to -1 to enables an unlimited number of blobs to be cached.
MaxBlobSize
Specifies the maximum blob size that can be saved and loaded to a database Blob field. If the value is set too low, this will result in stream read errors.