Here and other places they have strange spacing as seen in the picture:
Wondering what it means and what the purpose of it / if it's necessary or has some significance.
The spacing divides the 'half-lines' of the poem. This is fundamental to Old English metre, where each line of the poem consists of two half-lines, connected by alliteration.
By clicking the Meter option, the student may choose to have tooltips for any or all of the five different prevailing metrical theories.
The meter option can be selected from the Options pane on the left of the viewer: