To insert a table into the text, move the text cursor to the desired position and use one of the following methods:
Inserting quickly via the grid
Tables with a limited number of rows/columns and without further adjustments can be inserted directly via the grid (the table can also be further adjusted at any time afterwards):
Click on the small arrow of the icon 
on the ribbon tab Insert | group Table and move the mouse over the expanded grid. Above the grid, you will see how many rows and columns you are currently selecting (you will also see a preview of the table in the document).
As soon as the table has the desired dimensions, click with the mouse into the grid and TextMaker will insert the table into the document.
Tip: To move a table, select the entire table with the mouse or with the Select table command. Click in the middle of any cell of the selected table (keep the mouse button pressed) and drag the table to another place in the document. If you press the Ctrl key at the same time, the table will be copied.
Inserting via the dialog box with additional options
If you want to insert a table with any number of rows/columns and also adjust the inner margins, select the method via the dialog box:
Click on the icon itself on the ribbon tab Insert | group Table. Alternatively, click on the icon's small arrow and select the entry Insert table below the grid.
The program displays a dialog box in which you can specify the number of rows and columns the table should contain.
In the section below, you can also specify the inner margins for the table cells if necessary.
If you confirm with OK, TextMaker inserts the table into the document.