Open Table comes with 4 different widget types Standard, Wide, Tall & Button types. Each of them have their own views with some options specific to that view. Styling options remain same for each widget type which is only limited to the field & button styling.
To choose the widget type of your choice, go to Content > Basic > Widget Type.
For styling the fields & button of open table, go to Style tab there we have 2 other sub-tabs one for the Field styling options & other Button styling options.
To style the fields in an open table form, go to Style tab > Fields.
To style the “Find a Table” or “Reserve Now” button, go to Style tab > Button.