Exactly as @avantronica said - the “multiplier” values (which is set in the LFO menu) give you access to predefined increments that synchronize to common measure and bar lengths in a project. Most of this assumes you have patterns based around 16 steps. But ultimately, the LFO speed from the LFO speed knob is being multiplied by this value.
If you LFO speed is set to “2” and your multiplier is set to 16, one complete one wave “period” will take 4 whole notes. That is, for the LFO wave to go through one complete “cycle” if you want to think of it that way.
One important thing to note is that the multiplier can either be tempo-relative or non-tempo-relative, which is why the multiplier menu in the LFO settings has one “Mul” value for “X16” and another for just “16”. This is something that isn’t explained in the manual at all, so it’s hard to know exactly what the constant value behind the non-tempo-sync’d version of the LFO multipliers means exactly, but suffice to say that you won’t neatly line up with your step grid when using these ones.
One thing I’d highly recommend if you need good concise description of how the LFO works is to first watch this Loopop video section on the LFO (timestamp should be in the link automatically) https://youtu.be/csYWGW7Gwo4?t=1005
Second, I’d play around using the same technique he does: set the LFO to modulate pitch and then just play around. Once you’ve got a very clear audible marker for what the LFO is doing, you’ll very easily be able to hear how multipliers and LFO speed work together.
Edit: Oh, and another thing that is really nice is that LFO speed can go all the way to negative values, down to -64. So you can “invert” your LFO really easily. It’s a fun way to quickly “mess up” a track during performance to create variation and then recall to a temp save for the pattern.