Can I leave the Amsterdam airport during my layover en route to Canada?

You are holding a Lebanese passport. This means two things:

1. To enter the Schengen area, you need a visa.
2. You can transfer at Schiphol airport remaining airside and you do need an airport transit visa.

So "I require a short term visa for Amsterdam" this is entirely wrong: a) there's no such thing as a visa for Amsterdam, if you enter the Netherlands, you entered the Schengen area b) there's no such thing as a short term Schengen visa -- some countries have 24 or 72 hour visas, but the Schengen area doesn't c) again, just to get to Canada you don't require any kind of visa (especially not nonexisting ones).

To leave the airport, you need to enter the Schengen area. Whether that's for six seconds or six hours or six weeks, the rules are the same and you need a Schengen visitor visa.

Sources:

listing the third countries whose nationals must be in possession of visas when crossing the external borders and those whose nationals are exempt from that requirement

Who must apply for a Schengen visa

As stated in Timatic, the database used by airlines, when Canada is set:

Visa required

If there was an exemption for holders of Canadian visas, it would say so, but there isn't. It just exempts people that normally need airside transit visas from needing one.

So no, you cannot exit the airport without a visa.