To determine whether the data described in the tables is best modeled by a linear function or an exponential function, we need to analyze the patterns and trends in the data. Unfortunately, since you have mentioned tables but have not provided any specific data or tables, I am unable to assess the nature of the data or the relationship between the variables.
Please provide the specific data or tables for the costs of buying a small piece of land and a small car since 1990, and I'll be happy to help you determine whether a linear or exponential function is the best model for the data.