Organize your content in a custom-made grid.
You can create custom-made tables in a mural. You can add any amount of columns and rows, changing the sizes of the cells as you see fit.
Add a connector from the left menu.
Duplicate (Command/Control +D) it until you have the number of columns you need. Don't worry about getting the right distance between each column, you can adjust this later.
Hold down the SHIFT key and drag to select all lines
Select Change tip to make the lines straight
Click the Align option in the formatting menu and select Align left and then Distribute vertically to make sure the lines are even.
Create a link on both sides to decide the width of the table
Duplicate the lines with Comand/Control + D to your liking
Hold down SHIFT to select all lines
Select Align and then Distribute horizontally