Many of my shows are performed in people's homes, and sometimes in quite small rooms. I bring my own table, approximate size 2' 6" × 1' 6" (75cm × 50cm), and require about 2 feet (50cm) for me behind the table and a space of about 2 feet (50cm) between the table and the audience. Therefore a space of about 6 feet by 4 feet (2m × 1m) is sufficient. Children can be seated on the floor in front of me, and many children can occupy quite a small space (remember rows of seated children in school assemblies?)
I will work in any venue small or large.