Avoid bottom floats on pages with footnotes
Tip of the hat to David Carlisle.
\documentclass{book}
\usepackage[paperwidth=4.75in,paperheight=7.25in,
textwidth=4.5in,textheight=6.5in,
headsep=0.1in, footskip=0.15in,
marginratio=1:1]{geometry}
\usepackage[latin,english]{babel}
\usepackage{graphicx}
\usepackage{booktabs,lipsum}
\let\oldfootnote=\footnote
\def\footnote{\suppressfloats[b]\oldfootnote}
\begin{document}
\selectlanguage{latin}
\chapter{Errora}
Una imagine tabula, figura et \ae nigma.\footnote{translatio via google}.
\begin{figure}[htbp]
\centering
\includegraphics[width=0.3\textwidth]{example-image}
\caption{Uno pictorum}
\end{figure}
\begin{table}[b]%[htbp] %uncomment to see difference
\centering
\begin{tabular}{cccc}
\toprule
Error &Errors &error &errors\\
\bottomrule
\end{tabular}
\caption{Test}
\end{table}
\lipsum[1-6]
\end{document}
Based on the great answer from John Kormylo. This version is more robust: If the text with the footnote comes at the end of the page, John Kormylos version can break because a footnote after a pagebreak might suppress the float on the former page instead. This can be avoided by moving the code into the output routine:
\documentclass{book}
\usepackage[paperwidth=4.75in,paperheight=7.25in,
textwidth=4.5in,textheight=6.5in,
headsep=0.1in, footskip=0.15in,
marginratio=1:1]{geometry}
\usepackage[latin,english]{babel}
\usepackage{graphicx}
\usepackage{booktabs,lipsum}
\toks0{\ifvoid\footins\else\suppressfloats[b]\fi}
\output\expandafter{\the\toks0\the\output}
\begin{document}
\selectlanguage{latin}
\chapter{Errora}
Una\footnote{translatio via google} imagine\footnote{translatio via google} tabula\footnote{translatio via google}, figura\footnote{translatio via google} et\footnote{translatio via google} \ae\footnote{translatio via google} nigma.\footnote{translatio via google}.
Una\footnote{translatio via google} imagine\footnote{translatio via google} tabula\footnote{translatio via google}, figura\footnote{translatio via google} et\footnote{translatio via google} \ae\footnote{translatio via google} nigma.\footnote{translatio via google}.
Una\footnote{translatio via google} imagine\footnote{translatio via google} tabula\footnote{translatio via google}, figura\footnote{translatio via google} et\footnote{translatio via google} \ae\footnote{translatio via google} nigma.\footnote{translatio via google}.
Una\footnote{translatio via google} imagine\footnote{translatio via google} tabula\footnote{translatio via google}, figura\footnote{translatio via google} et\footnote{translatio via google} \ae\footnote{translatio via google} nigma.\footnote{translatio via google}.
Una\footnote{translatio via google} imagine\footnote{translatio via google} tabula\footnote{translatio via google}, figura\footnote{translatio via google} et\footnote{translatio via google} \ae\footnote{translatio via google} nigma.\footnote{translatio via google}.
\begin{figure}[htbp]
\centering
\includegraphics[width=0.3\textwidth]{example-image}
\caption{Uno pictorum}
\end{figure}
\begin{table}[b]%[htbp] %uncomment to see difference
\centering
\begin{tabular}{cccc}
\toprule
Error &Errors &error &errors\\
\bottomrule
\end{tabular}
\caption{Test}
\end{table}
\lipsum[1-6]
\end{document}