Here is what I do for a tile map effect that I find very simple:
I used TILED to export the entire map as one .png and place transparent triggers on a new layer on special events/block movement tiles/speed movement tiles,etc.
IIRC, HTML5 + a lot of objects = slowdowns.
Here is an example of this effect with the transparent blocks made visible
cheating a tile system in Construct2
But as for arrays in laymen's,
a data point in an array is an address.
Say you have an array #1 with datas (A), (B), (C)
[ or since Construct2 is zero-based, array
[0], array[1], array[2], etc. ]
Say you have a call for 1[A]
It tells the computer to find the variable at 1A
So it goes to column 1, location A and grabs that value.
Tile Maps use arrays for their X and Y values.
The gist would be knocking on those addresses doors, asking for their values, and then telling the system to create the tile that corresponds to that value at that X/Y