Introduction:
Excel is a powerful tool that allows users to create various types of charts to visualize data. These charts help in understanding trends, patterns, and relationships between different variables. In this question, we are asked to identify the type of Excel chart that does not exist.

Explanation:
The correct answer is option 'D', which states that a "Table chart" is not a type of Excel chart. Let's discuss the other options to understand why they are valid types of Excel charts.

a) Line chart:
A line chart is a type of chart that displays data points connected by straight lines. It is commonly used to show trends over time or compare multiple data sets. Line charts are helpful in visualizing the progression or regression of data.

b) Bar chart:
A bar chart is a type of chart that uses rectangular bars to represent data. The length of each bar corresponds to the value it represents. Bar charts are commonly used to compare discrete categories or show the distribution of data.

c) Scatter plot:
A scatter plot is a type of chart that displays data as a collection of points. Each point represents the value of two variables and is plotted on a coordinate plane. Scatter plots are useful for determining the relationship between two variables and identifying patterns or correlations.

d) Table chart:
The answer option 'D' states that a table chart is not a type of Excel chart. However, it is important to note that Excel does provide the functionality to create tables, but a table chart specifically refers to the visualization of data using rows and columns in a tabular format, rather than graphical representation.

Conclusion:
In conclusion, the type of Excel chart that does not exist is the "Table chart" (option 'D'). While Excel does provide tables for organizing and analyzing data, a table chart specifically refers to a graphical representation of data using rows and columns in a tabular format. The other options, such as line charts, bar charts, and scatter plots, are all valid types of Excel charts used for different purposes.