What is the most monetary settlement you can receive from a slip and fall injury?

That depends on the extent of your injuries. What are your past medical bills? Is there a need for future medical care? Are there past lost wages? Will there be future lost wages? What is the extent of the past and future Pain and Suffering? Are the Injuries permanent? There is no cap on damages to a slip and fall. The amount of damages depends on the above.

There is no ceiling. If there is no question about liability, it should be the total of the medical bills, the lost wages and whatever the jury believes the pain & suffering to be worth.