Why are tables important in Excel?

In order to make sense of a table, screen readers use header information to identify rows and columns. For this reason, it’s very important to accurately and correctly name headers.
In addition, screen readers keep track of their location in a table by counting table cells. If a table is nested within another table or if a cell is merged or split, the screen reader loses count and can’t provide helpful information about the table after that point. Blank cells in a table could also mislead someone using a screen reader into thinking that there is nothing more in the table.
Make sure tables don’t contain split cells, merged cells, nested tables, or completely blank rows or columns.