How do I display a data grid in PowerBI

Something like this: 

Notice that Patient C does not data for certain days and there is one Unk (Day 2 of Patient A).

= Table.FromRows({
    {
        "A","A1",
        1,
        1,
        "Pos",
        "https://cdn4.iconfinder.com/data/icons/keynote-and-powerpoint-icons/256/Plus-128.png"
    },
    {
        "A","A2",
        1,
        2,
        "Unk",
        ""
    },
    {
        "A","A3", 1,
        4,
        "Neg"  ,"https://cdn3.iconfinder.com/data/icons/softwaredemo/PNG/128x128/Minus_Circle_Green.png"
    },
    {
        "A","A4",
        1,
        6,
        "Pos",
        "https://cdn4.iconfinder.com/data/icons/keynote-and-powerpoint-icons/256/Plus-128.png"
    },
    {
        "A","A5",
        1,
        12,
        "Pos",
        "https://cdn4.iconfinder.com/data/icons/keynote-and-powerpoint-icons/256/Plus-128.png"
    },
    {
        "A","A6",
        1,
        24,
        "Pos","https://cdn4.iconfinder.com/data/icons/keynote-and-powerpoint-icons/256/Plus-128.png"
    },
    {
        "A","A7",
        1,
        48,
        "Neg" ,"https://cdn3.iconfinder.com/data/icons/softwaredemo/PNG/128x128/Minus_Circle_Green.png"
    },
    {
        "B","B1",
        2,
        1,
        "Neg" ,"https://cdn3.iconfinder.com/data/icons/softwaredemo/PNG/128x128/Minus_Circle_Green.png"
    },
    {
        "B","B2",
        2,
        2,
        "Pos" ,"https://cdn4.iconfinder.com/data/icons/keynote-and-powerpoint-icons/256/Plus-128.png"
    },
    {
        "B","B3",
        2,
        4,
        "Neg","https://cdn3.iconfinder.com/data/icons/softwaredemo/PNG/128x128/Minus_Circle_Green.png"
    },
    {
        "B","B4",
        2,
        6,
        "Neg","https://cdn3.iconfinder.com/data/icons/softwaredemo/PNG/128x128/Minus_Circle_Green.png"
    },
    {
        "B","B5",
        2,
        12,
        "Pos","https://cdn4.iconfinder.com/data/icons/keynote-and-powerpoint-icons/256/Plus-128.png"
    },
    {
        "B","B6",
        2,
        24,
        "Pos",
        "https://cdn4.iconfinder.com/data/icons/keynote-and-powerpoint-icons/256/Plus-128.png"
    },
    {
        "B","B7",
        2,
        48,
        "Pos",
        "https://cdn4.iconfinder.com/data/icons/keynote-and-powerpoint-icons/256/Plus-128.png"
    },
    {
        "B","B8",
        2,
        64,
        "Pos",
        "https://cdn4.iconfinder.com/data/icons/keynote-and-powerpoint-icons/256/Plus-128.png"
    },
    {
        "C","C1",
        3,
        1,
        "Neg" ,"https://cdn3.iconfinder.com/data/icons/softwaredemo/PNG/128x128/Minus_Circle_Green.png"
    },
    {
        "C","C2",
        3,
        2,
        "Pos" ,"https://cdn4.iconfinder.com/data/icons/keynote-and-powerpoint-icons/256/Plus-128.png"
    },
    {
        "C","C3",
        3,
        4,
        "Neg","https://cdn3.iconfinder.com/data/icons/softwaredemo/PNG/128x128/Minus_Circle_Green.png"
    },
    {
        "C","C4",
        3,
        6,
        "Neg","https://cdn3.iconfinder.com/data/icons/softwaredemo/PNG/128x128/Minus_Circle_Green.png"
    }
}, {
    "PatientID","PatientIDNumber",
    "YHelper",
    "StudyDay",
    "TestResults",
    "Image"
})

Though it has Known Limitations (see https://powerbi.microsoft.com/en-us/documentation/powerbi-service-r-visuals/#known-limitations), an R visual can do it.  See below for sample R script (12 lines without comments and blanks) and output.

library(ggplot2)    # Needed for ggplot
library(ggthemes)   # has a clean theme for ggplot2
library(tidyr)      # provide 'complete' function for empty heatmap cells

#Convert the (integer) StudyDay to a factor to avoid gaps in the X axis
dataset$StudyDay=with(dataset,factor(StudyDay))

#Fill missing data values, to avoid blank cells in the heatmap
dataset <- dataset %>% complete(PatientID, StudyDay)

# Avoid having to reference dataset$ each time in function calls
attach(dataset)

#Plot the dataset with TestResults to set the fill colour
ggplot(dataset, aes(x=StudyDay, y=PatientID, fill=TestResults)) +

#geom_tile to present as grid per https://www.rstudio.com/wp-content/uploads/2015/12/ggplot2-cheatsheet-2.0.pdf
  geom_tile(color="black", size=0.1) +

#Set the fill colours for TestResults
  scale_fill_manual(values = c("Pos" = "green", "Neg" = "red", "Unk" = "blue")) +

#Set square tiles
  coord_equal() +

#Apply tidy Tufte theme with no axis ticks
  theme_tufte(base_family="arial", ticks=FALSE) +

#Order by reverse PatientID
  scale_y_discrete(limits = rev(levels(PatientID)))