The Hammers will take on five of last season's Premier League top six over the next five weeks, starting with a visit of defending champions Manchester City next weekend.
Jarvis knows November will be an important month for Sam Allardyce's side but is confident they can do well after a bright start to the campaign.
He told the Sunday People: "We have had a great start to the season which has given us confidence but we have a really tough run of games now.
"November is going to be difficult. This is where we will get a taste of how we are going to do this season because you discover how much strength in depth you have over periods like this.
"Confidence is so important - it really is a massive factor in football.
"It's a tough division and this is going to be an important time but so far we have all worked hard to get into this position we are in.
"I'm sure collectively we can continue to do well."
Jarvis has been impressed by the approach of Allardyce since arriving from Wolves in the summer and says the manager reminds him of his old boss Mick McCarthy.
He said: "There are similarities between Big Sam and Mick McCarthy, who was my manager at Wolves.
"They both have an aura and presence about them. And if you do something wrong you know about it!
"Sam has put his own mix on things and a lot of his ideas are very heavy on stats.
"We have meetings about the opposition but he looks at our stats on set-pieces and everything else.
"It works for him and everyone is buying into it. It's the first time I have had this approach. He really likes it and I think it shows in what we do, there's no place to hide."