You can specify the maximim size of a single cache entry using the client.inet.cache.cacheEntryMaxSizeMB parameter, in the default.cfg file. This parameter controls the maximum size of a single cache entry, so that the cache does not get filled with very few, large cached entries. If a single entry size is more than this limit, then that entry will not be cached."
The default value for this parameter is 4, and it only accepts integer values.