To select multiple cells in a table, place the cursor in the first cell of the future range and move the cursor to the last cell of the range while keeping the left mouse button pressed. The selected cells will be highlighted with a light blue color.
You can also use the keyboard shortcuts to select the range.
To select an entire table, place the mouse cursor in any cell, move the cursor to the blue frame of the table and, when it looks like , left-click it. You may need this selection to perform operations on the entire table, for example, to resize all the cells of the table or to format all the content.