Your question relates to Pi's feelings when he is on his raft in the middle of a storm and he is absolutely terrified that he is going to be hit by a bolt of lightning that might kill him immediately or if not, destroy his raft. When a bolt of lightning strikes the sea very close to his raft, he is amazed and claims it as a miracle, explaining his feelings in the following way:
At moments of wonder, it is easy to avoid small thinking, to entertain thoughts that span the universe, that capture both thunder and tinkle, thick and thin, the near and the far.
Pi is trying to vocalise how the mind, in "moments of wonder" or after some epiphany that clearly draws our attention to the way in which we can think big thoughts that encompass both plenty and things that are much bigger than ourselves and also the tiny things in life. Pi describes a sensation of being aware of things that are much bigger than himself and his experience and also those tiny elements of his experience at one and the same time, and he is enlarged by the miracle that he has just witnessed.