Using a Scatter Plot Chart over a map

Hello everyone,

I have the two tables below :

Table 1

Table2

I want to achieve a scatter plot, over a map. The x,y position of a dot is artificially given and corresponds to the grid position over my map (so the dot is over the correct place).

I can't seem to find the formula to go in the column "occurences" so it returns the total number of rows in table 1 that match the place. 

I can't seem to figure out what fields to put where on my Scatter Plot Chart settngs so it shows what I want to achieve.

To me there is 2 ways of doing it and I can't seem to figure them out :

1) Create a column "occurences" (shown in red) so all the data i need for my scatter plot is in the same table.

2) Connect with a relationship Table1 and Table2 (which relationship ?)

I need help figuring out to set up the scatter plot. Please show screenshots of how you set it up ; I can't find myself 😞