To create and format a table in PowerPoint, follow these steps:

1. Open PowerPoint and create a new slide or open an existing presentation.
2. Select the slide where you want to insert the table.
3. Click on the “Insert” tab in the PowerPoint ribbon.
4. In the “Tables” section, click on the “Table” button.
5. A grid will appear with options to choose the number of rows and columns for your table. Click and drag to select the desired number of rows and columns.
6. Release the mouse button to insert the table onto the slide.

Now that you have inserted the table, you can format it:

1. Click inside the table to select it. The Table Tools Design and Table Tools Layout tabs will appear in the ribbon.
2. Use the options in the “Table Tools Design” tab to apply a table style, change the color scheme, or add borders to the table.
3. To change the font, font size, or alignment of the text within the table cells, select the text and use the formatting options in the “Home” tab of the ribbon.
4. To resize columns or rows, place your cursor over the column or row boundary until it changes to a double-headed arrow. Then, click and drag to adjust the size.
5. To add or delete rows and columns, click inside the table to display the table handles. Right-click on a handle, and choose the appropriate option from the context menu.
6. To merge or split cells, select the cells you want to modify, right-click, and choose the desired option from the context menu.
7. You can also apply shading or patterns to individual cells or groups of cells by selecting them and using the formatting options in the “Table Tools Design” tab.

Remember to save your PowerPoint presentation regularly to keep your changes.