Q:

Why such a strange plot?

I don't understand the problem with the plot I made; x values are supposed to go up to 46134 and y values are supposed to go up to 7094... On the plot, x values go to nearly 150000 and y values to 20000 ...!
And why are points joined in such a strange manner?
Code I used:
import matplotlib
import matplotlib.pyplot as plt

data = pd.DataFrame(
         [
             ["Albania",   28,   726],
             ["Armenia",   28,  1746],
             ["Austria",  543, 15307],
             ["Belgium", 7094, 46134]
         ],
         columns = [
             "Country",
             "y",
             "x"
         ]
    )
data

plt.plot(x, y, 'o-', color='red')

Plot:

A:

plt.plot(x, y, 'o-', color='red') should throw an error unless you have defined the variables x and y somewhere else in the program. 
Your x and y variables happen to hold numerical information that was able to be plotted, but since you wanted to plot the 'x' and 'y' columns from your dataframe, you probably meant to write:
plt.plot(data['x'], data['y'], 'o-', color='red')

