The game would be a walk over for them and although Fulham have been impressive in last games, they would find it difficult to beat Arsenal.
Having said that, Fulham aren't going to be an easy test, mind you that they (Fulham) have started very well this season, they drew with Liverpool in their first game of the season, they also have a very brilliant striker in Aleksandar Mitrovic, and i am pretty sure he is going to give the Arsenal defenders a really tough time. Don't get me wrong, of course Arsenal are the favorites to win, but Fulham are not going down without a fight, remember the smaller teams this season are giving the bigger teams a good run for their money, Leeds beat Chelsea, City had to struggle to get a draw with Newcastle, Palace and Fulham drew with Liverpool, Brighton and Brentford beat Manchester United, so it could be that season this time around were smaller teams don't back down, but fight.
The performance of Arsenal so far this season has been really good. As such, I do not think it would be a surprise if they won this game against Fulham as well. However, it is clear that this will not be a simple task for anyone to accomplish.
You know, Fulham has drawn against Liverpool and that is an indication of how good they can be if they work hard.
There is no way Arsenal should underestimate Fulham at all. Arsenal should always look to maximize the results from this match against Fulham. The reason for this is that after starting the season so well, if Arsenal does not succeed in getting three points out of this match, in my opinion, it will be considered a failure in some way.